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Birds may represent a useful animal model for studying human mental disorders
No full textIn basic neuropsychopharmacological research, some biobehavioral phenomena - e.g., population migration and navigation over long distances - are rarely considered because the most commonly used laboratory animals show little or no evidence of these phenomena. Nevertheless, they can be also relevant for the mechanism of human psychic aberrations. An annual migration is seen in migratory birds, certain marine mammals and several ungulates. For migratory birds, the time of departure is determined by the length of the photoperiod and is much less changeable than the chosen route. When navigating, migratory birds also use the direction and strength of the field lines of the Earth's magnetic field. Because humans also seem to exhibit a certain sensitivity to the Earth's magnetic field, the regulation in birds could also provide hints for research on human well-being. Some bird species have such highly developed cognitive abilities that this is considered proof of the possession of consciousness. Therefore, some birds may be suitable as experimental animals in neurobiological models for cognitive functions and for making the world of thought accessible. The dorsal diencephalic conduction system (DDCS) in humans is difficult to study due to its small size and complex architecture, but it is relatively well developed in more primitive vertebrates. For research into the primary interactions between the DDCS and the rest of the brain, the lamprey can be used as laboratory animal. There is manifold evidence that the DDCS along with forebrain and upper brainstem is of functional relevance and the significance of the DDCS in cortical-controlled networks could then be investigated in birds and verified in humans. </p
Investigating the role of physicochemical surface properties of polymeric pipe materials and a nanogel-based coating on microbial adhesion in unchlorinated drinking water
No full textPast research focused on the effect that different polymeric pipe materials have on biofilm formation in drinking water distribution systems (DWDS), to determine the best one to deliver safe drinking water to customers. However, results are often contradictory. Here, we studied the influence of five polymeric pipe materials and a surface modification with the anti-adhesive poly(N-isopropylmethacrylamide)-based nanogel coating on early-stage biofilms formation in unchlorinated drinking water in simulated DWDS conditions. Coupons made from two high-density polyethylene (HDPE-1 and HDPE-2), two unplasticized polyvinyl chloride (PVC-1 and PVC-2), and a molecularly oriented polyvinyl chloride (PVCO) were characterized in terms of surface topography, roughness, chemistry, and hydrophilicity. Biofilms were grown from real drinking water on the selected materials in a flow-chamber setup simulating DWDS conditions, with and without nutrient supplementation. Biofilm growth for 72 h with nutrient addition led to the same extensive biofilm formation on all surfaces. Without nutrients supplementation, 35-days experiments showed significant biofilm development on HDPE-1 only, despite comparable surface properties and chemistry to HDPE-2, and smoother and more homogeneous topography than PVCs. Application of the nanogel coating on HDPE-1 resulted in an average reduction of 87 % in biofilm development regardless under which condition. Microbial community analysis of biofilms by means of 16S rRNA gene sequencing showed a common core microbiome on all included materials in both nutrient-rich and oligotrophic conditions, with a high variability even within duplicates of the same material. Presented findings in combination with multiple studies available in the literature suggest that no conclusion can be made of whether PVC or PE is ultimately better in preventing biofilm formation in DWDS, because it is mainly due to the manufacturer. The suggested application of a surface modification with the anti-adhesive nanogel coating could uniform materials behaviour, acting as a localized biofilm control strategy for DWDS sections (hotspots) especially prone to biofilm development.</p
Mitigating carbon leakage under the EU ETS:How does state aid for indirect emission costs affect firm profits?
No full textNon-global climate policies, such as the EU Emissions Trading System (ETS), may suffer from carbon leakage, as firms subject to such policies may experience competitive disadvantages compared to firms operating in more loosely regulated areas. This process may make climate policies ineffective, thus undermining the efforts to fight climate change. Specifically, the EU ETS results in a carbon price that is partly passed through in electricity prices, negatively impacting EU electricity-intensive firms exposed to international competition. To avoid the latter, the EU awards so-called State Aid for Indirect Emission Costs to these firms. We empirically evaluate the extent to which firms obtained windfall profits from this aid in 17 EU countries and the UK between 2014 and 2019. We approximate the amount of aid received by firms based on EU legislation and estimate its effect on firm profits using a fixed effects regression model. Although we find that this policy may have mitigated the carbon leakage risk, we find evidence of over-generosity, with around 22% of beneficiaries possibly gaining windfall profits
Mapping the cellular heterogeneity of multiple sclerosis lesions:towards understanding lesion progression
No full textMultiple sclerosis (MS) is a progressive disease of the central nervous system (CNS) characterised by demyelination and inflammation. Affected areas – termed lesions – are differentiated in lesion types based on inflammatory activity, degree of demyelination, and anatomical location. The prevalence of certain lesion types and a larger overall lesion load correlate with disease progression. The cellular and molecular processes behind the formation, progression and potential resolution of MS lesions are not completely understood. Affected and involved cells derive both from the CNS and the immune system, and their relative contributions differ between lesion types. This thesis aimed to address this cellular heterogeneity to better understand lesions and thereby MS progression.To address the aim, we compared the gene activity profiles of lesions at the cellular and spatial level. We detected a novel rim around active lesions, which was predicted to precede the lesion core during the progression of lesions. These rims were characterised by the presence of ‘responsive’ microglia, a microglial state involved with phagocytosis and lipid metabolism, which we propose takes part in lesion expansion. Moreover, astrocytes in white matter lesions adopted gene activity profiles typically detected in grey matter astrocytes. We also studied interactions between microglia and the immune cells in the leptomeninges – a CNS barrier which tends to become inflamed during MS – and found perturbed cellular communications. Overall, the findings presented in this thesis highlight cellular, molecular and spatial processes in MS lesions and might pave the way towards new strategies for interfering in MS
How to scale beyond the niche? Fitting versus transforming strategies of grassroots initiatives and their impact on sustainability transitions
No full textThe question of how to increase the impact of grassroots initiatives via their scaling from niche to regime level is a key issue in transition studies. We add to the debate by analysing how organisational identities of energy cooperatives influence their scaling strategies. For this purpose, we use an explorative, qualitative research approach, conducted in collaboration with a federation of cooperatives in Germany. We identify several different identity types for the energy cooperatives studied (Classic GIs, Intermediary, Pragmatic, Tech drivers, & Economic-socials), observing that different identity types are associated with whether cooperatives pursue fit-and-conform or stretch-and-transform pathways. The findings are positioned in relation to broader debate on niche-regime dynamics. Namely, we highlight how the heterogeneity of types implies a need for nuance when thinking about scaling pathways. Our findings challenge simplistic policy narratives that prioritize expansion and instead call for nuanced support attuned to identity, agency and socio-spatial contexts.</p
Towards Automated Classification of Visual Hallucination Presence in Psychosis using Resting-State fMRI
No full textVisual hallucinations can severely impact the quality of life of affected individuals and are linked to greater disease severity in psychosis. To facilitate the detection of imaging biomarkers of visual hallucinations, we developed an automated pipeline to compare and evaluate feature extraction and classification methods using resting-state functional MRI scans from individuals with and without visual hallucinations. Five common functional connectivity features were assessed in this study: Regional Homogeneity, Voxel-Mirrored Homotopic Connectivity, Amplitude of Low Frequency Fluctuations, Fractional Amplitude of Low Frequency Fluctuations, and Eigenvector Centrality Mapping. We further evaluated the use of Pearson correlation in feature selection with different cutoff-values and employed a linear support vector machine for classification. The pipeline was validated on a dataset of 45 individuals, including people with psychosis and healthy controls. The model performance was evaluated based on the classification accuracy, sensitivity, specificity, as well as the interpretability of the feature weights. The code for the created pipeline is publicly available: https://github.com/LEO-UMCG/Visual_Hallucinations_Classification.Clinical relevance— Classification of patients based on biomarkers holds potential for complementing clinical measures, predicting future cases, and guiding personalized treatment of schizophrenia. The comparison of feature types and identification of imaging-based biomarkers in this study provide valuable insights for future research on VH classification and the underlying mechanisms of visual hallucinations
Networks and Supply-Side User Participation on Two-Sided Platforms
No full textTwo-sided platforms enable efficient interaction and contracting between supply-side and demand-side users. The participation of supply-side users is essential for platform operation because they provide services and products required by demand-side users. When participating on a two-sided platform, supply-side users are integrated into networks that connect them with both peers and cross-side users. This dissertation investigates how these networks influence supply-side user participation along two dimensions: individual performance and attrition.The first study is grounded in network effects, which emphasize that platform value increases with more users. However, it is unclear whether the performance of an individual supply-side user improves correspondingly with a larger user pool. Using panel data from an online freelancing platform, I find that while both same-sided network size and cross-sided network size independently enhance individual performance, their joint effect is substitutive, producing diminishing returns when both expand simultaneously.The second study captures interpersonal interactions and relational ties when supply-side users collaborate with peers and contract with demand-side users. Using social network analysis and a survival model, I find that supply-side users who are more embedded in peer networks are less likely to leave the platform. Moreover, the attrition-reducing benefits of peer network embeddedness are further amplified when supply-side users maintain diverse and stable relationships with demand-side users.This dissertation deepens the understanding of the social ties and relational context of two-sided platforms by comprehensively considering different user groups and identifying the network interplay within and between these groups
Large Owner Expropriation Threat and Stock Option Pay's Effect on Firm Risk-Taking Behaviors in Weak Institutions
No full textResearch Question/IssueThis study investigates the impact of managerial stock option pay on firm risk-taking behaviors in a weak institutional context, a critical question that has been overlooked by the literature. Specifically, we build on the comparative corporate governance perspective that emphasizes the implications of large shareholders' expropriation threat in weak institutions to develop predictions about their impact on the stock option's incentive alignment effect. We further explore the boundary conditions of such a relationship.Research Findings/InsightsBased on a sample of Chinese listed firms between 2006 and 2016, we find that a high level of large shareholders' expropriation threat weakens the effect of stock option value on firm risk-taking. We also find that such an adverse impact of large shareholders on the effect of stock option value is mitigated by the institutional factors that strengthen the protection of the interests of minority shareholders.Theoretical ImplicationsOur results underscore the importance of integrating the potential expropriation risk due to large shareholders and the institutional contexts into understanding the effectiveness of incentive-alignment governance practices such as stock option pay in the context with weak institutions (e.g., China).Practitioner/Policy ImplicationsOur findings offer insights for policy makers to better design the regulatory and institutional frameworks to increase the effectiveness of corporate governance practices. It also shows that firms in the context of weak institutions need to be more cognizant when adopting certain corporate governance practices (i.e., stock option pay for the incentive-alignment purpose)
Exploring the applications of molecularly imprinted polymers in drug delivery to the nervous system
No full textThe effective management of neurological disorders remains a major clinical challenge, as conventional therapeutics are often limited by poor nervous system permeability, suboptimal bioavailability, and systemic toxicity. These shortcomings have intensified interest in developing advanced drug delivery systems (DDSs) capable of targeted and controlled drug release. Molecularly imprinted polymers (MIPs), synthetic matrices endowed with tailor-made recognition sites, have emerged as a conceptually powerful platform for achieving molecular selectivity, structural stability, and programmable release kinetics. However, their translation into DDSs for neurological applications remains nascent and largely preclinical. Current evidence highlights a significant translational gap in MIP synthesis due to batch-to-batch variability, limited reproducibility, leaching of template molecules, residual monomer toxicity, and mass transport challenges. Inconsistent experimental design, lack of standardized characterization, and a focus on short-term cell viability instead of long-term biocompatibility further compromise therapeutic reliability and safety in vivo . This review delineates these limitations and outlines the strategic directions necessary for clinical advancement. Future progress will depend on the rational design of biodegradable, stimuli-responsive, and bio-orthogonal MIPs that achieve predictable release and safe clearance in neural environments. A shift from experimental methods to rational, data-driven design and manufacturing is imperative to achieve the requisite reproducibility and scalability. Collectively, while MIPs have yet to achieve clinical maturity, their unique molecular precision and adaptability position them as a promising framework for next-generation DDS. However, this potential is contingent upon a concerted, interdisciplinary effort to bridge persistent material and biological gaps in neuroscience and beyond.</p
Unravelling the policy-to-implementation gap:Climate Adaptation Governance Arrangements in medium-sized cities
No full textUrban areas are increasingly facing climate-related risks that outpace the implementation of adaptation measures, often attributed to a persistent policy-to-implementation gap. Bridging this gap requires a deeper understanding of the underlying governance dynamics. This paper adopts a governance arrangement perspective, drawing on recent insights from urban climate adaptation literature to introduce a Climate Adaptation Governance Arrangement (CAGA) framework. This framework examines institutional conditions that either enable or constrain climate adaptation planning, helping to unravel barriers to effective implementation. It was applied to analyse climate adaptation efforts in the medium-sized city of Groningen (the Netherlands). Medium-sized cities are less prevalent in adaptation research, even though growing evidence suggests that their limited resources and strong interpersonal relationships can foster innovative adaptation strategies. Through a policy analysis and interviews with stakeholders from local and regional governments and society, we found that Groningen has been innovative in linking climate adaptation to spatial quality, which makes climate adaptation a central goal in urban planning. However, the development of a holistic and integrated approach remains hindered by existing path dependencies, leading to an overemphasis and usage of water-related measures and budgets