Publikationer från Uppsala Universitet
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The influence of host-environment interactions in shaping insect microbiota : limitations and considerations
No full textThis thesis investigates insect-associated microbiota and the statistical approaches used to study them, with a particular focus on how environmental context shapes microbial community composition. The work encompasses three main research aims. First, we examined the microbiota of Anopheles mosquitoes, assessing how breeding-site characteristics, such as habitat type, and the physicochemical properties of aquatic environments, influence site and larval microbial communities and the link between those. We also explored whether a trace of adult host-seeking behavior, specifically preference for human or cattle hosts, can be recognized in mosquito microbial composition, and how these patterns reflect the surrounding environment. Second, we investigated microbial communities in Cicadellidae (Membracoidea) and their parasitoid wasps (Hymenoptera and Strepsiptera) to evaluate whether parasitization influences leafhopper symbionts. By sampling host–parasitoid pairs, we identified instances in which microbial strains occurred in both insects, suggesting that transient microbial transfer may occur during parasitization and could, over evolutionary time, contribute to stable symbiotic associations. Finally, we addressed methodological challenges in microbial ecology by developing a framework for choosing a threshold for rarefation, a widely used normalization procedure for 16S rRNA sequencing data. The resulting tool, Sibyl, provides a data-driven approach for threshold selection and offers users clearer insights into how preprocessing decisions may influence downstream analyses. Environmental context emerges as a major determinant of insect microbiota, influencing through a complex network of interactions, both the microbial pools available to insects and the communities they ultimately harbor
Evidence for a Clinically Meaningful Effect of no-Touch Harvesting Technique on Vein Graft Patency : A Bayesian Reanalysis of the SWEDEGRAFT Trial
No full textCross-Genre Learning for Old English Poetry POS Tagging
No full textPoetry has always distinguished itself from other literary genres in many ways, including grammatically and syntactically. These differences are evident not only in modern literature but also in earlier stages. Linguistic analysis tools struggle to address these differences. This paper focuses on the dichotomy between Old English poetry and prose, specifically in the context of the POS tagging task. Two annotated corpora representing each genre were analyzed to show that there are several types of structural differences between Old English poetry and prose. For POS tagging, we conduct experiments on both a detailed tag set with over 200 tags and a mapping to the UPOS tag set with 17 tags. We establish a baseline and conduct two cross-genre experiments to investigate the effect of different proportions of prose and poetry data. Across both tag sets, our results indicate that if the divergence between two genres is substantial, simply increasing the quantity of training data from the support genre does not necessarily improve prediction accuracy. However, incorporating even a small amount of target data can lead to better performance compared to excluding it entirely. This study not only highlights the linguistic differences between Old English poetry and prose but also emphasizes the importance of developing effective NLP tools for underrepresented historical languages across all genres
Beyond the dichotomy : Deeds and explorations as a mutually enhancing dyad in undergraduate mathematics education
No full textStudents’ development of routines is essential to learning, particularly in STEM studies where there is a goal of preparing students for directly applying mathematics for practical ends. We hypothesize that this impacts on how they engage with routines. We report from an empirical study which explores different types of routines that undergraduate students engage in when using an animation tool to model motion in a real-world context. Drawing on commognitive theory, we conducted a fine-grained qualitative analysis of the discursive activity of one group of three engineering students. Rather than aiming for a broad generalization, the study uses this dataset to examine the mechanisms through which students shift between deed-oriented and explorative routines. The analysis shows that these routines do not function as separate forms of engagement, rather they developed as a mutually reinforcing dyad – a dyadic relationship. We argue that recognizing this relationship provides a refined lens for understanding how environments may support possibilities not only for practical learning, but also for discursive learning
G. Woolf, I. Bultrighini & C. Norman, eds, Sanctuaries and experience. Knowledge, practice and space in the ancient world (Potsdamer altertumswissenschaftliche Beiträge 83),Stuttgart: Franz Steiner Verlag 2024
No full textSmaka i alla fall! : En kvalitativ studie om förskollärares förhållningssätt under måltidssituationen
No full textDenna studie undersökte hur förskollärare förhöll sig till barn samt hur barns delaktighet och inflytande uttrycktes under måltidssituationer i förskolan. Detta skedde med kvalitativa observationer och fältanteckningar från tre förskolor där måltidssituationerna analyserades utifrån ett sociokulturellt perspektiv samt barnrättsperspektiv. På vardera förskola observerades två avdelningar, en yngre barns avdelning och en äldre barns avdelning, med fokus på att se skillnader i förhållningssätten. Resultaten visade att barns delaktighet varierade mellan förskolorna. På vissa avdelningar uppmuntrades barn att uttrycka sina preferenser, servera själva och delta i dialoger som stöttade språket. På andra avdelningar präglades måltiden av rutiner och regler där förskollärare styrde situationen vilket bidrog till att barnens möjlighet att vara aktiva och medutforskande deltagare minskade. Samspel mellan barn och förskollärare framstod som avgörande. Förskollärare som använde öppna frågor, lugnt tonläge och språklig stöttning skapade en inkluderande måltidsmiljö där lärandetillfällen även kunde ske. När måltiden är till för barnen skapades en hälsofrämjande måltidssituation där barnen fick möjlighet att samtala och upptäcka nya smaker med både kropp och sinne. När måltiden används som en pedagogisk situation snarare än rutin ökade barnens förutsättningar för lärande, delaktighet och positiva matupplevelser. Resultaten visade även i att det finns vissa skillnader i bemötandet och förhållningssättet gentemot yngre och äldre barn. För de yngre barnen var det i större utsträckning fokus på omsorg medan de äldre barnen uppmuntrades att vara självständiga med viss stöttning av förskollärarna. Studien visade att ett medvetet förhållningssätt gjorde måltiden till en viktig plats för barns utveckling och lärande
Matrix product state based band Lanczos solver for quantum cluster approaches
No full textWe present a matrix-product state (MPS) based band Lanczos method as solver for quantum cluster methods such as the variational cluster approximation. While a na & iuml;ve implementation of MPS as cluster solver would barely improve its range of applicability, we show that our approach makes it possible to treat cluster geometries well beyond the reach of exact diagonalization methods. The key modifications we introduce are a continuous energy truncation combined with a convergence criterion that is more robust against approximation errors introduced by the MPS representation and provides a bound to deviations in the resulting Green's function. The potential of the resulting cluster solver is demonstrated by computing the self-energy functional for the single-band Hubbard model at half filling in the strongly correlated regime, on different cluster geometries. Here, we find that only when treating large cluster sizes, observables can be extrapolated to the thermodynamic limit, which we demonstrate at the example of the staggered magnetization. Treating clusters sizes with up to 6 x 6 sites we obtain significant improvement over the extrapolation accessible with exact diagonalization solvers when comparing with quantum Monte Carlo results. Finally, we illustrate the applicability of the MPS cluster solver to more complex models by calculating spectral properties as relevant for the electron-doped cuprate CaCuO2
Dynamic assembly of a large multidomain ribozyme visualized by cryo-electron microscopy
No full textMany RNAs rely on their 3D structures for function. While acquiring functional 3D structures, certain RNAs form misfolded, non-functional states ('kinetic traps'). Instead, other RNAs sequentially assemble into their functional conformations over pre-folded scaffolds. Elucidating the principles of RNA sequential assembly is thus important to understand how RNAs avoid the formation of misfolded, non-functional states. Integrating single-particle electron cryomicroscopy (cryo-EM), image processing, in solution small-angle X-ray scattering (SAXS), EM-driven molecular dynamics (MD) simulations, structure-based mutagenesis, and enzymatic assays, we have visualized the sequential multidomain assembly of a self-splicing ribozyme of biomedical and bioengineering significance. Our work reveals a distinct dynamic interplay of helical subdomains in the ribozyme's 5'-terminal scaffold, which acts as a gate to control the docking of 3'-terminal domains. We identify specific conserved and functionally important secondary structure motifs as the key players for orchestrating the energetically inexpensive conformational changes that lead to the productive formation of the catalytic pocket. Our work provides a near-atomic resolution molecular movie of a large multidomain RNA assembling into its functionally active conformation and establishes a basis for understanding how RNA avoids the formation of non-functional 'kinetic traps'
Livet efter hjärtstopp – en litteraturöversikt om existentiella upplevelser och psykiska konsekvenser
No full textABSTRACT Introduction: Cardiac arrest is one of the most common causes of death in Sweden. When a cardiac arrest occurs, the heart’s pumping ability ceases and oxygen deprivation develops. Rapid cardiopulmonary resuscitation is crucial for survival. Thanks to improved medical care, more individuals now survive, but many experience lasting psychological and existential consequences such as anxiety, depression, and a changed outlook on life. Existential and psychological recovery is complex and requires support. Nurses play a central role in identifying these needs and providing person-centred care that promotes holistic recovery. Aim: To describe survivors’ experiences after cardiac arrest with a focus on existential experiences and mental consequences. Method: A qualitative literature review with a descriptive design was conducted. Ten scientific articles published between 2016 and 2023 were included from the databases PubMed, CINAHL, and PsycInfo. The analysis was conducted based on the study’s aim, focusing on the results of the included articles. Results: The Analysis process resulted in five categories that together illuminate the patients’ experiences after a cardiac arrest. The existential experiences involved meaning-making, a changed perspective on life, and an increased awareness of life’s fragility. Several participants described a deep sense of gratitude, reflections on the meaning of life, and a strengthened spirituality. The mental consequences included worry, anxiety, and loneliness, often related to memory gaps and cognitive difficulties. A lack of information intensified these feelings, whereas clear and repeated information contributed to a greater sense of security and strengthened involvement in the recovery process. Conclusion: Surviving cardiac arrest entails existential and mental challenges that require continuous support and clear information. A holistic nursing approach that combines Orem’s self-care theory with an existential perspective can promote recovery and quality of life. Keywords: Existential experiences, Cardiac arrest, Mental consequences, Survivors
A methodology for image reproduction in virtual environments applied to an agricultural assistance function
No full textWith the digitalization of mobile work machines, camera-based monitoring of machine conditions is becoming increasingly important. In the present application of an agricultural cultivator, the wear condition of its tines is monitored using a camera system and intelligent image evaluation. Extensive test drives are needed to develop such systems. This work proposes a methodology to reproduce real image data in high-resolution virtual environments to enable realistic virtual testing processes. The methodology consists of subprocesses for parameter identification and image reconstruction. In the context of parameter identification, accurate camera modelling is essential, requiring parameterization based on real camera calibration data, including image distortion. The subsequent image reconstruction process covers the fine-tuning of the virtual environment and its camera model, as well as the recording of the virtually generated images. After describing the methodology, the processes are evaluated using the example of the tool monitoring system for the above-mentioned cultivator. A comparison of the virtually generated images with the images from the real camera shows a good match of the images. Visible deviations are due to usage-related deformations of the real system. However, the deviations are small and the image quality high enough that the image recognition of the monitoring system can identify the cultivator tines and their elements. The evaluation shows that the potential for improving the methodology lies mainly in the automation of its process steps. It also highlights the importance of the robustness of tool monitoring systems with regard to geometric changes to the overall system