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  • Rubak, Adam
    et al.
    Karlstad University.
    Taheri, Javid
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). Queen's University Belfast, United Kingdom.
    Machine Learning for Predictive Resource Scaling of Microservices on Kubernetes Platforms2023In: Proceedings of the IEEE/ACM 16th International Conference on Utility and Cloud Computing, Association for Computing Machinery (ACM), 2023, p. 1-8Conference paper (Refereed)
    Abstract [en]

    Resource scaling is the process of adjusting the amount of resources allocated to a system or a service according to the changing demand. For microservices, resource scaling can be done at different levels, such as the container, the pod, or the cluster. However, the current approaches for resource scaling are not good enough because they rely on reactive or rule-based methods that do not account for the dynamic and complex nature of microservices. These methods often lead to over-provisioning or under-provisioning of resources, both affecting the quality of service and the cost efficiency. To address these issues, this work focuses on testing multiple machine learning approaches to optimize the pod dimensioning problem for Kubernetes platforms through predicting resource requirements for an upscaled number of users. The proposed approach aims to address the limitations of the standard Horizontal Pod Autoscaler (HPA), which often results in resource wastage or suboptimal performance. The results were promising and demonstrated high precision and performance of multiple ML models to accurately forecast future resource needs. 

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  • Taheri, Javid
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). Queen’s University Belfast, UK.
    Gördén, Arvid
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Al-Dulaimy, Auday
    Mälardalen University, Sweden.
    Using Machine Learning to Predict the Exact Resource Usage of Microservice Chains2023In: Proceedings of the IEEE/ACM 16th International Conference on Utility and Cloud Computing, Association for Computing Machinery (ACM), 2023, p. 1-9Conference paper (Refereed)
    Abstract [en]

    Cloud computing offers a wide range of services, but it comes with some challenges. One of these challenges is to predict the resource utilization of the nodes that run applications and services. This is especially relevant for container-based platforms such as Kubernetes. Predicting the resource utilization of a Kubernetes cluster can help optimize the performance, reliability, and cost-effectiveness of the platform. This paper focuses on how well different resources in a cluster can be predicted using machine learning techniques. The approach consists of three main steps: data collection and extraction, data pre-processing and analysis, and resource prediction. The data collection step involves stressing the system with a load-generator (called Locust) and collecting data from Locust and Kubernetes with the use of Prometheus. The data pre-processing and extraction step involves extracting relevant data and transforming it into a suitable format for the machine learning models. The final step involves applying different machine learning models to the data and evaluating their accuracy. The results illustrate that different machine learning techniques can predict resources accurately. 

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  • Walan, Susanne
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Primary school students’ perceptions of artificial intelligence – for good or bad2024In: International journal of technology and design education, ISSN 0957-7572, E-ISSN 1573-1804Article in journal (Refereed)
    Abstract [en]

    Since the end of 2022, global discussions on Artificial Intelligence (AI) have surged, influencing diverse societal groups, such as teachers, students and policymakers. This case study focuses on Swedish primary school students aged 11–12. The aim is to examine their cognitive and affective perceptions of AI and their current usage. Data, comprising a pre-test, focus group interviews, and post-lesson evaluation reports, were analysed using a fusion of Mitcham’s philosophical framework of technology with a behavioural component, and the four basic pillars of AI literacy. Results revealed students’ cognitive perceptions encompassing AI as both a machine and a concept with or without human attributes. Affective perceptions were mixed, with students expressing positive views on AI’s support in studies and practical tasks, alongside concerns about rapid development, job loss, privacy invasion, and potential harm. Regarding AI usage, students initially explored various AI tools, emphasising the need for regulations to slow down and contemplate consequences. This study provides insights into primary school students perceptions and use of AI, serving as a foundation for further exploration of AI literacy in education contexts and considerations for policy makers to take into account, listening to children’s voices. 

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  • Tkachuk, Anton
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Tkachuk, M. M.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Design of truss structures with multiple eigenfrequency constraints via rank minimization2024In: Computers & structures, ISSN 0045-7949, E-ISSN 1879-2243, Vol. 299, article id 107392Article in journal (Refereed)
    Abstract [en]

    Rank deficiency of the dynamic stiffness matrix is an indicator for resonance of a structure at a given frequency. This indicator can be exploited as a heuristic optimization objective to achieve resonance at several frequencies. Log-det heuristic provides a tractable surrogate function for matrix rank in the case of affine dependency of stiffness and mass matrices on design parameters, which applies to truss structures. Reducing the rank of the dynamic stiffness matrix for higher frequencies implies that the matrix is not semi-positive definite. For this case, the log-det heuristic is valid with a combination of interior-point methods and Fazel’s semi-definite embedding via linear matrix inequalities. Further constraints on the fundamental frequency and compliance can be easily added within the framework as linear matrix inequalities. Several successful numerical examples illustrate the performance of the approach. 

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  • Sebhatu, Samuel Petros
    et al.
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Service Research Center (from 2013). Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Karlstad Business School (from 2013).
    Hamdan, Qusay
    University of Ghent, Belgium; University of Namur, Belgium; University of Pécs, Hungary.
    Fisk, Raymond P.
    Texas State University, USA.
    Conceptualizing service ethics for the complexity of modern service interactions2024In: Service Industries Journal, ISSN 0264-2069, E-ISSN 1743-9507Article in journal (Refereed)
    Abstract [en]

    The emergence of digital service platforms enabled numerous interaction effects that remain largely unexplored, especially when it comes to the intended or unintended impacts on non-customers. This article conceptualises service ethics for modern interactions enabled by digital service platforms. The conceptual framework is illustrated through two narratives of non-customers intentionally and unintentionally exploited by customer interactions enabled by digital service platforms. By integrating theoretical insights with illustrative narratives, this article demonstrates the potential impact of digital service platforms on non-customer well-being, highlighting instances of exploitation and unintended consequences. This study advances service research by focusing on non-customers who might experience intentional or unintentional exploitation. Furthermore, this article outlines a future research agenda for exploring and advancing the understanding of service ethics along with implications for fostering ethical business practices and shaping ethical societal norms.

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  • Lundell, Sara
    et al.
    Umeå University, Sweden.
    Isaksson, Ulf
    Umeå University, Sweden.
    Coe, Anna-Britt
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Department of Social and Psychological Studies (from 2013). Umeå University, Sweden.
    Harrison, Samantha L.
    Teesside University, England.
    Hajdarevic, Senada
    Umeå University, Sweden.
    Swedish translation and psychometric testing of the Self-Conscious Emotions in COPD Questionnaire2024In: Respiratory Medicine, ISSN 0954-6111, E-ISSN 1532-3064, Vol. 226, article id 107624Article in journal (Refereed)
    Abstract [en]

    Assessment of self-conscious emotions is important to develop tailored interventions for people with chronic obstructive pulmonary disease (COPD). Previous instruments have largely been developed for mental health populations. The Self -Conscious Emotions in COPD Questionnaire was the first instrument to assess selfconscious emotions in people with COPD, but it was only available in English. The aim was to translate the Self -Conscious Emotions in COPD Questionnaire into Swedish and to evaluate its psychometric properties and internal structure in a Swedish context. The translation process included forward and backward translation, a multidisciplinary meeting, assessment of content validity, and cognitive interviews. The translated instrument was tested in a sample of 173 people with COPD between September 2021 and September 2022. Parallel analysis (PA), exploratory factor analysis (EFA), and test -retest reliability was performed. The content validity index (CVI) for the instrument was 0.88. Based on the PA, an EFA with a two -factor solution was conducted, with a high Cronbach's alpha (0.786-0.821), and one item about self -blame was excluded. The two factors were labelled: The burden of living with a disability and The desire to hide vulnerability. Test -retest reliability showed no difference between scale scores on factor or item level, except for one item. The Swedish Self -Conscious Emotions in COPD showed good validity and reliability. One item was excluded from the two subscales, indicating that the instrument needs to be further developed to cover the concept of selfblame. The instrument is expected to be a valuable tool for assessing self-conscious emotions in people with COPD.

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  • Bartura, Khelifa
    et al.
    Norwegian School of Sport Sciences, Norway.
    Abrahamsen, Frank Eirik
    Norwegian School of Sport Sciences, Norway.
    Gustafsson, Henrik
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Department of Educational Studies (from 2013). Norwegian School of Sport Sciences, Norway.
    Hatzigeorgiadis, Antonis
    University of Thessaly, Greece.
    Gorgulu, Recep
    Bursa Uludag University, Turkey.
    Ironic processes of concentration and suppression under pressure: A study on rifle shooting in Norwegian elite biathletes2024In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 34, no 5, article id e14647Article in journal (Refereed)
    Abstract [en]

    In rifle shooting, suppressing unwanted thoughts can backfire in one's performance, causing athletes to behave contrary to their desired intention and further deteriorate their performance.PurposeThis study examined how priming attentional and negative cues affected participants' shooting performances toward ironic error targets under cognitive load conditions in Stroop task across two experiments.MethodsSemi-elite biathletes (Experiment 1, n = 10; Experiment 2, n = 9) participated in the study. The study used a within-subject quasi-experimental design, particularly a one-way repeated measures multivariate analysis of variance and a 2 x 2 fully repeated measures analysis of variance, to determine the participants' hit rates and shooting response times (RTs). In both experiments, the participants completed the reverse-Stroop-based target shooting performance under low- and high-cognitive load conditions while receiving frequent priming attentional and negative cues.ResultsThe findings from Experiment 1 suggest that regulating repetitive priming attentional thoughts is efficacious in mitigating the likelihood of ironic performance errors and interference effects. The results of Experiment 2 show that repetitive priming negative cues resulted in negligible ironic error hit rates and slower RTs in target hits under high-cognitive load conditions. The Bayesian analyses provided evidence supporting the null hypotheses.ConclusionTrying to control repetitive priming attentional and negative thoughts reduces ironic performance errors to a similar degree under cognitive load conditions among biathletes, regardless of interference effects. Further research is needed to determine the effectiveness of suppressing task-relevant negative instructions in reducing the likelihood of ironic performance errors under pressure.

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  • Henriksson, Gunnar
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Germgård, Ulf
    Lindstroem, Mikael
    Royal Institute of Technology, KTH, Sweden.
    A review on chemical mechanisms of kraft pulping2024In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669Article in journal (Refereed)
    Abstract [en]

    Kraft pulping of wood is based on efficient depolymerization and solubilization of lignin, while cellulose is relatively undamaged. Non-cellulose cell wall polysaccharides are however in some cases heavily degraded, especially pectin and to a lesser degree also glucomannan while, xylan is relatively stable. In this mini-review, the most important reactions in lignin and polysaccharide degradation in kraft pulping are described, both the technically favorable and the problematic reactions, and the chemical background to discuss the advantages and drawbacks of the process. An attempt to put the different reactions in the perspective of the goals of the pulping process is made and a special focus is on the development of color in the pulp fiber during the kraft pulping.

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  • Thomsen, Morten Feldtfos
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Department of Language, Literature and Intercultural Studies (from 2013).
    'Evil never dies, right?' Monstrous mediation in the A Nightmare on Elm Street Film Series2024In: Journal of Aesthetics & Culture, E-ISSN 2000-4214, Vol. 16, no 1, article id 2350092Article in journal (Refereed)
    Abstract [en]

    This article investigates images of mediation in the A Nightmare on Elm Street film series, focusing primarily on its main antagonist, Freddy Krueger, and his monstrous uses of media. Employing Eugene Thacker's concept of "dark media", as well as Gary Heba's reading of the Nightmare series as centering on the confrontation between youth and the dominant societal order of patriarchal capitalism, this article argues that the series articulates a highly ambivalent image of mediation, which is intimately connected to its thematic interest in issues concerning power and emancipation. Moreover, it argues that this ambivalent image of mediation ultimately constitutes a self-reflexive engagement with the potential cultural work of the Nightmare series itself.

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  • Petersson, Jöran
    et al.
    Malmö universitet, Sverige.
    van Bommel, Jorryt
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). Karlstad University, Faculty of Health, Science and Technology (starting 2013), Science, Mathematics and Engineering Education Research.
    Teaching quality during mathematics lessons2024In: Skrifter från SMDF, Nr 18: Mediating mathematics: Proceedings of MADIF 14, the fourteenth research conference of the Swedish Society for Research in Mathematics Education. Örebro, March 19–20, 2024 / [ed] Johan Häggström; Cecilia Kilhamn; Linda Mattsson; Hanna Palmér; Miguel Perez; Kerstin Pettersson; Ann-Sofi Röj-Lindberg ; Anna Teledahl, Göteborg, 2024, Vol. 18, p. 141-141Conference paper (Refereed)
    Abstract [en]

    This presentation focuses changes in elements of teaching quality during three parts of a mathematics lesson; start, middle and end. 64 grade 7 lessons were analysed using these partitions, forming a time series that shows decreasing quality for most elements (e.g., Modelling) from start to end of a lesson. Few elements showed an increase of quality (e.g., Intellectual Challenge). The structure of the lessons (whole class at start and individual work during middle and end) may partially account for a possible decrease. Even so, a decrease in quality is not desirable and implications on students’ learning are of concern.

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  • Aronsson, Ingela
    et al.
    Umeå University, Sweden.
    Stigsdotter Neely, Anna
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Department of Social and Psychological Studies (from 2013). Luleå University of Technology, Sweden.
    Boraxbekk, Carl-Johan
    University of Copenhagen, Denmark; Umeå University, Sweden; Copenhagen University Hospital Bispebjerg, Denmark, .
    Eskilsson, Therese
    Umeå University, Sweden.
    Gavelin, Hanna M.
    Umeå University, Sweden.
    "Recovery activities are needed every step of the way"-exploring the process of long-term recovery in people previously diagnosed with exhaustion disorder2024In: BMC Psychology, E-ISSN 2050-7283, Vol. 12, no 1, article id 248Article in journal (Refereed)
    Abstract [en]

    Background Sick-leave rates are high due to stress-related illnesses, but little is still known about the process of recovery from these conditions. The aim of this study was to explore the experiences of the recovery process, 6 to 10 years after treatment in people previously diagnosed with exhaustion disorder (ED), focusing on facilitators and barriers for the process of recovery from ED, and recovery activities experienced as helpful during the recovery process.Method Thirty-eight participants (average age: 52 years, 32 females) previously diagnosed with ED were interviewed with semi-structured interviews 6-10 years after undergoing treatment. The interviews were analyzed with thematic analysis.Results Three themes resulted from the analysis. The first theme, "A long and rocky road", summarizes the fluctuating path to feeling better and emphasizes barriers and facilitators that affected the process of recovery, with a focus on external life events and the participants' own behaviors. Facilitators were changing workplace, receiving support, a reduction in stressors, and changed behaviors. Barriers were a poor work environment, caregiver responsibilities, negative life events and lack of support. The second theme "Recovery activities are needed every step of the way" describes how both the need for recovery activities and the types of activities experienced as helpful changed during the recovery process, from low-effort recovery activities for long periods of time to shorter and more active recovery activities. Recovery activities were described as important for self-care but hard to prioritize in everyday life. The last theme, "Reorienting to a new place", captures the struggle to cope with the remaining impact of ED, and how internal facilitators in terms of understanding and acceptance were important to reorient and adjust to a new way of functioning.Conclusions Recovering from ED is a long and ongoing process where recovery activities are needed every step of the way. Our results highlight the importance of supporting personal recovery and long-term behavioral change, addressing individual stressors that may perpetuate the condition, and adjusting recovery activities according to where the person is in the recovery process.Trial registration ClinicalTrials.gov: NCT0073772. Registered on March 8, 2017. This study was pre-registered on Open Science Framework (osf.io).

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  • Kumar, Divyaratan
    et al.
    Linköping University, Sweden.
    Franco, Leandro R.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Abdou, Nicole
    Chalmers University of Technology, Sweden.
    Shu, Rui
    Linköping University, Sweden.
    Martinelli, Anna
    Chalmers University of Technology, Swede.
    Araujo, Moyses
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013). Uppsala University, Sweden.
    Gladisch, Johannes
    Linköping University, Sweden.
    Gueskine, Viktor
    Linköping University, Sweden.
    Crispin, Reverant
    Linköping University, Sweden.
    Khan, Ziyauddin
    Linköping University, Sweden.
    Water-in-Polymer Salt Electrolyte for Long-Life Rechargeable Aqueous Zinc-Lignin Battery2024In: Energy & Environmental Materials, E-ISSN 2575-0356Article in journal (Refereed)
    Abstract [en]

    Zinc metal batteries (ZnBs) are poised as the next-generation energy storage solution, complementing lithium-ion batteries, thanks to their cost-effectiveness and safety advantages. These benefits originate from the abundance of zinc and its compatibility with non-flammable aqueous electrolytes. However, the inherent instability of zinc in aqueous environments, manifested through hydrogen evolution reactions (HER) and dendritic growth, has hindered commercialization due to poor cycling stability. Enter potassium polyacrylate (PAAK)-based water-in-polymer salt electrolyte (WiPSE), a novel variant of water-in-salt electrolytes (WiSE), designed to mitigate side reactions associated with water redox processes, thereby enhancing the cyclic stability of ZnBs. In this study, WiPSE was employed in ZnBs featuring lignin and carbon composites as cathode materials. Our research highlights the crucial function of acrylate groups from WiPSE in stabilizing the ionic flux on the surface of the Zn electrode. This stabilization promotes the parallel deposition of Zn along the (002) plane, resulting in a significant reduction in dendritic growth. Notably, our sustainable Zn-lignin battery showcases remarkable cyclic stability, retaining 80% of its initial capacity after 8000 cycles at a high current rate (1 A g-1) and maintaining over 75% capacity retention up to 2000 cycles at a low current rate (0.2 A g-1). This study showcases the practical application of WiPSE for the development of low-cost, dendrite-free, and scalable ZnBs. A dendrite-free and long-life cycle Zn-lignin battery was demonstrated using water-in-polymer salt electrolyte. 

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  • As'ad, Nabila
    et al.
    University of Porto, Portugal.
    Patricio, Lia
    University of Porto, Portugal.
    Koskela-Huotari, Kaisa
    Stockholm School of Economics, Sweden.
    Edvardsson, Bo
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Service Research Center (from 2013).
    Understanding service ecosystem dynamics: a typology2024In: Journal of Service Management, ISSN 1757-5818, E-ISSN 1757-5826, Vol. 35, no 6, p. 159-184Article in journal (Refereed)
    Abstract [en]

    PurposeThe service environment is becoming increasingly turbulent, leading to calls for a systemic understanding of it as a set of dynamic service ecosystems. This paper advances this understanding by developing a typology of service ecosystem dynamics that explains the varying interplay between change and stability within the service environment through distinct behavioral patterns exhibited by service ecosystems over time. Design/methodology/approachThis study builds upon a systematic literature review of service ecosystems literature and uses system dynamics as a method theory to abductively analyze extant literature and develop a typology of service ecosystem dynamics. FindingsThe paper identifies three types of service ecosystem dynamics-behavioral patterns of service ecosystems-and explains how they unfold through self-adjustment processes and changes within different systemic leverage points. The typology of service ecosystem dynamics consists of (1) reproduction (i.e. stable behavioral pattern), (2) reconfiguration (i.e. unstable behavioral pattern) and (3) transition (i.e. disrupting, shifting behavioral pattern). Practical implicationsThe typology enables practitioners to gain a deeper understanding of their service environment by discerning the behavioral patterns exhibited by the constituent service ecosystems. This, in turn, supports them in devising more effective strategies for navigating through it. Originality/valueThe paper provides a precise definition of service ecosystem dynamics and shows how the identified three types of dynamics can be used as a lens to empirically examine change and stability in the service environment. It also offers a set of research directions for tackling service research challenges.

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  • Erlandsson, Ann
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Asmonaite, Giedre
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Jonsson, Bror
    Norwegian Institute for Nature Research, Norway.
    Greenberg, Larry
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Using qPCR to Identify Potential Effects of Thermal Conditions during Embryogenesis on Mitochondrial DNA Copy Number in Juvenile Brown Trout Salmo trutta2024In: Fishes, E-ISSN 2410-3888, Vol. 9, no 4, article id 142Article in journal (Refereed)
    Abstract [en]

    Changes in the number, structure, and function of mitochondria during the early life stages of animals can play an important role for an organism's metabolic rate, growth, and health. Previous studies have shown that juvenile brown trout (Salmo trutta) subjected to elevated temperatures during the embryonic stage respond phenotypically with a reduced metabolic rate. The aim of this study was to explore if embryonic temperature affects the mitochondria content of young brown trout and as such explains the previously found differences in metabolic rates. Here, we optimize a quantitative PCR (qPCR) method for the mitochondria cytochrome c oxidase subunit I gene, and then use the method as a proxy for mitochondrial DNA content. We hypothesize that young trout subjected to elevated temperatures during the embryonic stage respond phenotypically with a reduced mitochondrial DNA content. To test this hypothesis, we subjected brown trout to either control ambient (4.4 +/- 1.5 degrees C) or elevated temperatures (7.1 +/- 0.6 degrees C) during embryogenesis. Subsequently, we extracted DNA from liver and white muscle tissue of juvenile brown trout from the two different incubation temperature treatments and successively optimized qPCR for mitochondrial DNA. We found that the amount of mitochondria DNA in liver tissue was 18 times higher than in white muscle tissue, but there was no significant difference in mitochondria content in liver or muscle tissue between brown trout exposed to elevated and ambient control temperatures during embryogenesis. We conclude that reduced metabolic rate is not likely associated with mitochondria DNA content. We also suggest that qPCR is a simple and cost-effective method to quantify mitochondria DNA in frozen and partly degraded tissue from different treatment groups and a useful proxy for identification of differences in mitochondria number.

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  • Shry, Samuel
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Harbicht, Andrew
    Department of Fisheries and Ocens,, Canada.
    Forsberg, Hanna
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Nilsson, Anders
    Lund University, Sweden.
    Hellstroem, Gustav
    Swedish University ofAgricultural Sciences, Sweden.
    Österling, Martin
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Calles, Olle
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Challenges in downstream dam passage and the effect of dam removal on Atlantic salmon (Salmo salar) smolt migrations2024In: Journal of Fish Biology, ISSN 0022-1112, E-ISSN 1095-8649Article in journal (Refereed)
    Abstract [en]

    Migration is critical for life-cycle completion in diadromous fish species. River connectivity is vital in facilitating these large-scale movement events, but the extent of present-day river fragmentation can interfere with these migrations. Fish passage solutions (FPSs) are commonly implemented with the aim of improving river connectivity. In our study, we investigated the performance of two types of FPSs, spill regimes and complete dam removal, on Atlantic salmon (Salmo salar) smolt migrations. We used acoustic telemetry to monitor migration behavior and passage success of 120 wild smolts released in three different groups/sites: one group with two dams to pass to reach the river mouth, a second group with one dam to pass, and a control group without any barriers to pass (upstream of a recently removed hydroelectric dam). Smolt passage probabilities were similar for the two studied dams (87% and 86%) but showed variation in path choice, delay times, and loss rates. Passage success was influenced by several factors, such as body size, diel period, and water temperature, but not flow. Cumulative passage success to the river mouth was 61%, with most individuals being lost within lentic river stretches, either in the forebays of hydroelectric power stations or in naturally wide river stretches. Within the recently rehabilitated river sections (post dam removal), passage speeds were significantly faster than all other sections of the river (post-rehabilitation x<overline> = 56.1 km/day) with significantly faster speeds compared to pre-rehabilitation (pre-x<overline> = 28.0 km/day). Our findings provide valuable information on the benefits of dam removal and highlight the need for further rehabilitation measures in upriver reaches where barriers still affect downstream passage.

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  • Asghari, Hamid
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Department of Educational Studies (from 2013).
    Vocational didactics based on industrial teachers’ stories: A study on vocational teaching and vocational learning in Swedish vocational upper secondary schools2024In: Scandinavian Journal of Vocations in Development, E-ISSN 2464-4153, Vol. 9, no 1, p. 91-109Article in journal (Refereed)
    Abstract [en]

    Based on industrial teachers’ narrated experiences of teaching and meeting students at Swedish vocational high schools, this study will provide a definition of the concept of vocational didactics. The study is based on two central pillars: 1) the concept of vocational didactics and 2) narrative research. The concept of vocational didactics is elaborated on the basis of previous research, and stories are further described as the theoretical and methodological starting points. The results show that ten themes about vocational didactics (vocational teaching and vocational learning) emerge from the industrial teachers’ stories. The common denominator in the themes is the concept of occupation, which is related to employability as an industrial worker. The vocational didactics and its constituent themes, which are context-bound and change as a result of technological development and societal changes, are processed and discussed in relation to the workshop environment (master-apprentice tradition) and school environment. The conclusion is that vocational didactics comprises teaching and learning professional skills and enabling students to become professional practitioners in a profession and a labour market that change continuously in step with technological development and social change.

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  • Fyrberg Yngfalk, Anna
    et al.
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Karlstad Business School (from 2013). Malardalen University, Sweden.
    Fellesson, Markus
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Karlstad Business School (from 2013). Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Service Research Center (from 2013).
    Service with(out) a smile: The reproduction of gendered consumer violence2024In: Marketing Theory, ISSN 1470-5931, E-ISSN 1741-301XArticle in journal (Refereed)
    Abstract [en]

    This paper critically examines consumer violations of employees in the Nordic retail sector. In bringing these violations to light, we analyse how employees become subjectified by the ideals of consumer sovereignty, and how service work is discursively and practically aligned with the notion of the sovereign consumer. We demonstrate how the discourse of consumer sovereignty intersects with gendered service work and the expectations of feminine sexual availability, and how this alignment reproduces gender and power inequalities. Drawing on studies of consumer violence and misbehaviour and feminist research on service work, we argue that the patterns of subjugation and consumer abuse are intrinsically embedded both in the ideal of consumer sovereignty itself and in the strategies that employees use to constitute themselves within prevailing market and gender orders. The study provides a critical understanding of how consumer sovereignty operates in tandem with gender structures to form subjugating practices that both enable and normalise consumer violations.

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  • Ericson Öberg, Anna
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013). Volvo Construction Equipment, Sweden.
    Goncalves Machado, Carla
    Jönköping University, Sweden.
    Stålberg, Lina
    Volvo Construction Equipment, Sweden; Mälardalen University, Sweden.
    Diagnostics of Opportunities – A Dialogue Tool for Addressing Digital Factory Maturity2024In: Sustainable Production through Advanced Manufacturing, Intelligent Automation andWork Integrated Learning / [ed] Joel Andersson, Shrikant Joshi, Lennart Malmsköld, Fabian Hanning, IOS Press, 2024, Vol. 52, p. 395-406Conference paper (Refereed)
    Abstract [en]

    For over 15 years, the concept of Industry 4.0, now transitioning into Industry 5.0, has been a focal point for the manufacturing sector. Yet, the success of companies in embracing digital transformation varies. There are numerous models and assessment tools for assessing digital readiness and maturity. Several models have been developed over the years, but firms also realize no "one-size-fits-all" exists when testing them. Previous studies show that firms must take charge of their own digital transformation (DT) journey to find a path that suits their specific needs.This qualitative paper is driven by a case study supported by a within-case analysis conducted with a heavy-machine industry with fourteen production plants worldwide – data collected from 2020 to 2023. Volvo Construction Equipment (Volvo CE), created Factory 4 Tomorrow (F4T) to address Industry 4.0. The central challenge for the F4T initiative was how to facilitate an inside-outside approach to identify an inclusive maturity model that emphasizes learning and collaboration. A diagnostic of opportunities model was created to aid the organisation’s transformation journey. It aimed to support all plants by evaluating their maturity in digital transformation, identifying gaps, and support in prioritising. Unlike traditional models that assess and compare plant levels, this model aimed to foster awareness and alignment, establishing a shared language. Thus, a unique model was explicitly crafted for the firm. The process of developing the model itself enhanced awareness and alignment. Therefore, this paper explores the development process - failures and successes - to compile a digital transformation maturity model tailor-made to a firm’s needs and goals. The objective is to offer comprehensive advice for firms to implement DT initiatives effectively in a way that suits them. 

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  • Ringqvist, Josef
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Karlstad Business School (from 2013).
    Integrating Collective Voice within Job Demands–Resources Theory2024In: Work, Employment and Society, ISSN 0950-0170, E-ISSN 1469-8722, p. 1-20Article in journal (Refereed)
    Abstract [en]

    Drawing on insights from the sociology of work, this article contributes to job demands–resources (JD-R) theory by arguing that collective employee voice should be considered within the framework as an antecedent of job demands and job resources. An empirical test is offered to substantiate the theoretical argument, hypothesizing that collective voice – measured as trade union influence at the workplace level – reduces job demands and increases job resources. Based on the notion that some jobs may be inherently demanding, an additional hypothesis posits that collective voice balances demands with job resources by supplementing resources particularly where demands are high. Drawing on data from the European Social Survey covering 27 countries, results of multi-level analyses reveal that while not associated negatively with job demands, collective voice enhances job resources, particularly where demands are high. On this basis the article encourages further sociologically informed analyses of the JD-R model.

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  • Chantziara, Katerina
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Fatigue, defects and failure mechanisms in high strength tool steels at different fatigue life regimes2024Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Fatigue response of metallic materials is considered of significant importance, particularly for high-demanding applications. It is proved that most of the engineering materials do not exhibit a conventional fatigue limit in the high cycle fatigue regime, but rather display a continuously decreasing stress-life response at even longer lifetimes. Consequently, investigations of the various failure mechanisms taking place are essential, especially at the high and very high cycle fatigue regimes.The development of new ultrasonic testing equipment made the fatigue testing beyond 107 life cycles possible in a much shorter time, enabling testing with fatigue fractures at stress levels lower than the traditionally proposed “fatigue limit”. Nowadays, a classification of fatigue life regimes in Low Cycle Fatigue (LCF), High Cycle Fatigue (HCF) and Very High Cycle Fatigue (VHCF) is commonly used. The main reasons for this specific grading are: i) the need for safe design of components and ii) the fact that the failure mechanisms are particular in each of the LCF, HCF and VHCF regimes.The main goal of the present thesis is to address the fatigue response of high strength tool steels. Considering the novel alterations in composition and production methods in alloy development, materials of high-quality are continuously being introduced to the market; understanding the fatigue response of these materials is crucial for potential utilization across diverse industries and applications. The generation of fatigue experimental data, the analysis of the different types of fatigue initiation defects found in each material, as well as the investigation of the fatigue mechanisms occurring during cyclic loading are the main subjects analyzed throughout the present study. 

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  • Wik, Malin
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Karlstad Business School (from 2013).
    Prototyping with purpose: Increasing participatory design with malleable interactive prototypes2024Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This work emphasises the long-standing focus on democratisation in the participatory design field by analysing how participation can be achieved (the pragmatics of participation) and how participation can be increased (the politics of participation) through malleable interactive prototyping. 

    Malleable interactive prototyping refers to the design of digital prototypes of IT systems that are open enough for a designer and a user to collaboratively design and re-design. The interactiveness allows the user to experience the interaction with the system and its design and also allows for redesign during the interaction.

    This type of prototyping is explored in the collaborative design of an IT system between a designer and citizens at a hospital, and in a short series of co-design workshops with young learners as designers within a component of their digital competence education in upper secondary school. Through a qualitative analysis, this work demonstrates that malleable interactive prototyping increases participation and participatory design. Four conclusions are proposed for the participatory design field: malleable interactive prototyping gives users an informed voice in the design process, allows users to collaboratively design an IT system with a designer, facilitates mutual learning between designer and user, and increases the ecological validity of the collaborative design. Furthermore, the explorations contribute to the education field by showing that malleable interactive prototyping can explicate future use and the user as well as the role of the user and the IT system for young learners, thus enabling young learners to experience democratic IT systems design processes. These conclusions suggest that school policy writers should consider including a socio-technical perspective in the computational-focused curriculum and that educators should contemplate the delivery of this education across all programmes.

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  • Lundqvist, Johanna
    et al.
    Mälardalen University, Sweden.
    Franzén, Karin
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Department of Educational Studies (from 2013).
    Munter, Ann-Charlotte
    Mälardalen University, Sweden.
    Early childhood mathematics: A case study2021In: Early years, ISSN 0957-5146, E-ISSN 1472-4421, Vol. 43, no 4-5, p. 763-777Article in journal (Refereed)
    Abstract [en]

    The aim is to investigate early childhood mathematics in a preschool unit in Sweden. A mixed-method research approach and a case study research design were used. Three preschool staff members and 19 children were enrolled. Data were collected by means of observations and a focus group interview. Numerical and thematic analyses were conducted. The mean value of ratings of early childhood mathematics in the preschool unit approached ‘good’ (m = 4.5) and can be described by means of six themes: one to ten mathematics; a short question and a short answer; embedded mathematical concepts in everyday routines and play activities; whole-group mathematical circle times incorporating support for younger children and those who are struggling; accessible robots, materials and tools, and small group mathematics. The study could form a basis for discussions on such matters as early childhood mathematics and differentiation in preschools, both in Sweden and in other countries.

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  • Islami, Lejla
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Envisioning Usable Privacy in Smart Environments: A Technical and Intercultural Perspective2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Smart environments provide users with a large number of new services that will improve their lives, such as smarter and more efficient transportation, advanced smart home services, and pervasive healthcare. Yet, they also have the potential for collecting staggering amounts of personal information, which, if misused, poses a multitude of privacy threats to users ranging from tracking, stalking to monitoring and profiling. Consequently, the users’ right to informational self-determination is at stake in smart environments. Therefore, there is a need for solutions that empower individuals with control over their data in smart environments. Privacy-Enhancing Technologies (PETs) and privacy by design and by default can help to protect users’ privacy. In particular, usable Privacy-Enhancing Identity Management (PE-IdM) can re-establish user control and, thus, informational self-determination by offering users a selection of meaningful preference-based privacy settings that they could choose from to lessen the configuration burden of privacy settings. However, different privacy trade-offs need to be considered and managed for the configuration of the identity management system, as well as various factors influencing users’ privacy preferences. Guidelines for the design of usable management of privacy settings that address varying end-user preferences for control, location sharing and privacy conflicting goals are needed. The objective of this thesis is to propose viable approaches for enforcing usable PE-IdM for smart environments, with a focus on vehicular ad hoc networks (VANETs). To that end, we unravel the technical state of the art regarding the problem space and solutions. We employ qualitative and quantitative empirical Human-Computer Interaction (HCI) research methods to investigate different users’ privacy preferences and factors affecting such preferences. Our results demonstrate a cultural and regional influence on willingness to share location data and preferences for trade-offs for location privacy. Based on our results, we elicit end-users and design requirements and propose high-level design guidelines for usable PE-IdM for VANETs. These guidelines aim to simplify privacy and identity management for users by offering selectable settings that will cater for their different privacy needs and preferences.

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  • Löfdahl, Annica
    et al.
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Department of Educational Studies (from 2013).
    Löfgren, Håkan
    Linköping University, Sweden.
    Narratives of Teachers and Teacher Unions in Swedish Facebook Rebellion Groups2023In: Professions & Professionalism, E-ISSN 1893-1049, Vol. 12, no 3Article in journal (Refereed)
    Abstract [en]

    This study examines narratives about the teaching profession and teacher unions that Swedish teachers jointly produce in two teachers’ rebellion groups on Facebook, which is followed by a total of around 20,000 teachers. A sample of 33 posts and 2,445 comments were analysed using a narrative approach. The findings highlight narratives in which teachers wish to return to “the good old days”, struggle with everyday frustrations, call for a strike as an immediate solution, and describe hypothetical futures presenting the opportunity for proactive action and call teacher unions to dialogue rather than wait for them to satisfy the teachers’ demands.

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    Narratives of Teachers and Teacher Unions in Swedish Facebook Rebellion Groups
  • Wahlin, Åsa
    et al.
    Malmö University, Sweden.
    Lindmark, Ulrika
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Health Sciences (from 2013).
    Norderyd, Ola
    Jönköping University, Sweden; Region Jönköping County, Sweden.
    Association of sense of coherence and periodontal disease severity, in two cross-sectional studies2024In: International Journal of Dental Hygiene, ISSN 1601-5029, E-ISSN 1601-5037Article in journal (Refereed)
    Abstract [en]

    Objectives: To investigate the association between the individuals’ level of sense of coherence (SOC) and periodontal disease severity. Methods: The study populations originated from two stratified cross-sectional random samples of residents in a medium-sized Swedish city in 2003 and 2013, respectively. The final samples constituted 491 individuals in 2003 and 538 individuals in 2013. The samples were classified into three groups according to the severity of periodontitis (no/minor, moderate and severe). The 13-item Swedish version of Antonovsky’s “Orientation to life” questionnaire, measuring the individual’s SOC, was filled out. Descriptive statistics were performed as well as multinomial logistic regression analysis. Dependent variable was the severity of periodontal disease and independent variables, age in years, presently smoking and education at university level. Results: In the multinomial regression analysis, smoking, age, and total SOC score were significantly associated with severe periodontitis at both examinations. The strongest predictor of severe periodontal disease was smoking. The total SOC score did not differ between the examinations, but there was a statistically significant difference in two of the SOC dimensions, manageability (lower), and comprehensibility (higher), over time. Conclusions: Individuals with severe periodontitis had significantly lower SOC compared to subjects periodontally having no/minor periodontal disease. Smoking was the strongest overall predictor of having severe periodontitis. 

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