Publikationer från Uppsala Universitet
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Highly adaptable deep-learning platform for automated detection and analysis of vesicle exocytosis
No full textActivity recognition in live-cell imaging is labor-intensive and requires significant human effort. Existing automated analysis tools are largely limited in versatility. We present the Intelligent Vesicle Exocytosis Analysis (IVEA) platform, an ImageJ plugin for automated, reliable analysis of fluorescence-labeled vesicle fusion events and other burst-like activity. IVEA includes three specialized modules for detecting: (1) synaptic transmission in neurons, (2) single-vesicle exocytosis in any cell type, and (3) nano-sensor-detected exocytosis. Each module uses distinct techniques, including deep learning, allowing the detection of rare events often missed by humans at a speed estimated to be approximately 60 times faster than manual analysis. IVEA's versatility can be expanded by refining or training new models via an integrated interface. With its impressive speed and remarkable accuracy, IVEA represents a seminal advancement in exocytosis image analysis and other burst-like fluorescence fluctuations applicable to a wide range of microscope types and fluorescent dyes
A Study of RS-LMTO-ASA on Ni and the CurieTemperature of Ni Thin Films
No full textA convergence study was made on the exchange constants of Ni with respect to computational parameters in RS-LMTO-ASA. Specifically the convergence was examined with respect to structure constant cutoff distance, system size and recursion depth. It was found that the exchange parameters converge for all three. The system converges quickly for the cutoff distance, in accordance with the use of tight binding parameters. For the system size fluctuations are apparent up to a threshold value. Interestingly while the exchange parameters converge for recursion depth study of the magnon dispersion show that there exists a sweetspot before convergence where the calculated properties match experiments best. However examination of the density of states showed that this is likely coincidental. Using the exchange parameters calculated from RS-LMTO-ASA a metropolis Monte carlo study was made of thin film Ni examining the change of Curie temperature with respect to thickness and magnetic interaction length. It is found in accordance with earlier experimental work that the Curie temperature decreases with thickness in accordance with finite size scaling theory and that this is independent of the stacking. It is also found that including longer magnetic interactions gives a stronger decrease witch mathces the experimental results better, as found in earlier theoretical work on a model system. With regard to the shift exponent it is however found that it is not appropriate to calculate it using a least squares regression to the reduced Curie temperature data. This is due to a high dependence on where one places the thick film limit. As no theoretical predictions exists for this limit the shift exponents extracted through this method are arbitrary.
Pain threshold and pain tolerance in young people with self-injurious behavior : A systematic review and meta-analysis
No full textBackground and Aims Pain sensitivity has been proposed as a contributing factor to self-injurious behavior (SIB). Meta-analytic results show that individuals with SIB have lower pain sensitivity than healthy controls (HC). However, these findings are primarily based on adult populations. SIB typically begins in the early teen years and is most prevalent among youth. The aim of the present meta-analysis was to quantify the association of SIB and pain thresholds and pain tolerance in young people aged 10 to 24 years. Methods We performed a systematic search of the literature (MEDLINE, Web of Science Core Collection and PsycINFO) up until 10 December 2024. Titles, abstracts, and full texts were independently screened by multiple reviewers. Random-effects meta-analysis was performed on two pain-related outcomes: pain threshold and pain tolerance. The Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline was followed. Quality assessment was performed using the Newcastle-Ottawa scale. Results Of 5200 screened studies, 221 full-text articles were retrieved whereof 8 studies fulfilled the criteria (n=592). Participants ranged from 10 to 22 years. Meta-analysis demonstrated statistically significantly higher pain threshold (Hedges’ g = 0.79, 95 % CI [0.13, 1.46]) in individuals with SIB compared to HC and no statistically significant difference in pain tolerance (Hedges’ g = 0.39, 95 % CI [-0.02; 0.79], p = 0.056). Conclusions Young people with SIB demonstrate higher pain thresholds compared to healthy controls, suggesting that lower sensitivity to painful stimulation may be a risk factor for SIB across developmental stages. Future studies should examine whether this association is independent of psychiatric comorbidity and other confounding factors
Simulating Complex Particle Dynamics with Graph Neural Networks
No full textParticles are fundamental tools for simulating a wide range of physical systems, yet modeling complex particle dynamics remains a major computational challenge. This thesis explores graph neural network (GNN)-based simulators as a versatile solution to this problem, examining their effectiveness and practical limitations. Using the Graph Network-based Simulator (GNS), experiments demonstrate an ability to capture intricate behaviors across multiple domains, including water, sand, and viscoelastic materials, within a unified computational framework. Although achieving promising accuracy in short-term predictions, the model can develop instabilities during extended simulations, particularly when encountering out-of-distribution scenarios like boundary crossings. These findings highlight the potential of GNN-based methods for rapid prototyping and exploratory analysis while recognizing the need for improved robustness and scalability for broader scientific and industrial applicability.
A complex between IF2 and NusA suggests early coupling of transcription-translation
No full textThe main function of translation initiation factors is to assist ribosomes in selecting the correct reading frame on an mRNA. This process has been extensively studied with the help of reconstituted in vitro systems, but the dynamics in living cells have not been characterized. In this study, we performed single-molecule tracking of the bacterial initiation factors IF2, IF3, as well as the initiator fMet-tRNAfMet directly in growing Escherichia coli cells. Our results reveal the kinetics of factor association with the ribosome and, among other things, highlight the respective antagonistic roles of IF2 and IF3 in the process. Importantly, our comparisons of in vivo binding kinetics of two naturally occurring isoforms of IF2 reveal that the longer IF2α isoform directly interacts with the transcriptional factor NusA, a finding further corroborated by pull-down and cross-linking experiments. Our results suggest that this interaction may promote formation of a coupled transcription-translation complex early in the translation cycle, motivating further structural studies to validate the mechanism. We further show that cells with compromised binding between IF2α and NusA display slow adaptation to new growth conditions
Unravelling Geological Structures Controlling the Groundwater Table in the Blötberget Mine Area
No full textNatural resource consumption, one of the main drivers of carbon emissions, is steadily rising at a concerning pace. For raw materials and mineral resources, this means an annual increase, a trend expected to intensify with the global transition to green energy and sustainable industries. In particular, the demand for rare earth elements, often found in iron ore deposits, is projected to grow significantly. While reducing the global resource demand is crucial for achieving a sustainable future, developing environmentally responsible mining practices is equally essential. Re-opening of historical mines may be a more sustainable alternative to traditional exploitation, mainly due to its reduced environmental disturbance. Since transportation infrastructure are already in place and overburden has previously been removed, re-opening such sites can reduce additional ecosystem disruption. However, successful re-opening requires a comprehensive understanding of hydrogeological conditions in the area. This study investigates the Blötberget mine in Dalarna, Sweden as a previously closed mine to be reactivated. Following its closure, the mine rapidly flooded, and to evaluate its re-opening potential, this research analyses borehole data to map groundwater levels and examine the influence of geological structures on groundwater behaviour. The results indicate that the groundwater flow is significantly affected by several local geological features. Several of the faults in the area were found to function as hydraulic barriers, impeding groundwater flow and causing major variations in the water table. In contrast, other faults acted as conduits, forming aquifer zones in the host rock and likely promote groundwater flow locally. Notable, one significant drainage was identified, creating a local depression in the water table and thus marking the possible need for adapted dewatering upon re-opening of the mine. These findings highlight the significance of a detailed structural and hydrogeological analysis when considering reactivation of former mine sites. To further improve the understanding of groundwater dynamics in the area, future studies incorporating additional data such as topographic, subsurface, geological and temporal weather information would be highly valuable. Detailed analyses investigating such additional datasets could support reliable groundwater modelling, as well as high-frequency monitoring to capture seasonal fluctuations in the water table
”I dag skall jag gästa ditt hem.” (Luk. 19:5) : En studie av teologiska förutsättningar för att välsigna hem i Svenska kyrkan
No full textThe purpose of this essay is to examine the theological premises within the Church of Sweden for blessing homes. The study is based on theoretical and methodological concepts such as divine presence and divine absence, and employs a content-oriented ideational analysis in combination with theory formation and theory development. The analysis covers the liturgical order for house blessings in the Evangelical-Lutheran Church of Finland, the corresponding liturgical order in the Church of Norway, as well as two liturgical orders used in the parishes of Häverö-Edebo and Harbo-Östervåla, both of which contain elements for the blessing or dedication of objects used in church life. The analysis identifies the underlying theological ideas and structures that shape the blessing practices, as well as the consequences these ideas entail. Based on the study of existing liturgical orders for the dedication and blessing of church objects, together with examples of house blessings from other Nordic churches, the essay develops four theoretical models: private prayer, prayer of use, character-altering blessing, and transformative blessing. The results show that there are theological grounds for house blessings within the Church of Sweden, provided that these are understood within the framework of the first three models. The first three models differ in their view of the necessity of a formalized ritual but share an emphasis on God’s omnipresence and the absence of an ontological change. The transformative blessing, on the other hand, appears problematic in a Lutheran context, as it introduces a distinction between the sacred and the profane that lacks support in the theological tradition of the Church of Sweden
Higher Education AI Policies : A Document Analysis of University Guidelines
No full textArtificial Intelligence (AI) has been highlighted as a potentially disruptive force across several industries and in higher education. Research has suggested that education and upskilling of citizens should adopt a broad approach, not only focusing on experts, for better nationwide AI readiness. This study investigates the content of AI policies in higher education by analysing official documents from Swedish universities. It identifies key themes and patterns, comparing them with related research and international guidelines. Expanding on the results of the study, it develops a dynamic alignment model for higher education AI policy (DAMHEAP) which, grounded in institutional theory, highlights strategic, pedagogical, ethical and legal, operational and adaptive alignments. This model, together with 10 practical recommendations, provides a roadmap for higher education institutions to develop and maintain AI policies that are pedagogically relevant, ethically responsible and adaptive to technological change
Simplified modeling of ice formation over airfoils
No full textIce accretion on wind turbine blades in cold climates poses significant challenges to aerodynamic performance and operational reliability. This study presents a computationally efficient framework for predicting rime ice formation, combining potential flow panel methods with Lagrangian droplet tracking. The model is validated against experimental data from the Ice Prediction Workshop and benchmarked against FENSAP-ICE simulations. Key findings demonstrate strong agreement in velocity fields (especially near the leading edge region) and collection efficiency and ice thickness predictions, with two-way coupling improving the estimation of the ice thickness. For rime ice, the simplified model achieves superior agreement with experimental data compared to FENSAP-ICE simulations, particularly when implementing geometry updates every 300–600 s, enabling a two-way coupling. Glaze ice evaluations reveal limitations in neglecting liquid film dynamics, though the model still outperforms conventional methods. The proposed methodology reduces computational costs of at least one order of magnitude compared to full three-dimensional Reynolds-Average Navier–Stokes simulations while maintaining predictive accuracy for critical ice-prone regions. Results underscore the viability of hybrid potential flow/Lagrangian methods for real-time icing predictions, with future extensions targeting phase-change thermodynamics for enhanced glaze ice modeling