| 1. |
- Fagerlind, Magnus, et al.
(författare)
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Modeling the effect of acylated homoserine lactone antagonists in Pseudomonas aeruginosa
- 2005
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Ingår i: Biosystems (Amsterdam. Print). - : Elsevier. - 0303-2647 .- 1872-8324. ; 80:2, s. 201-213
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Tidskriftsartikel (refereegranskat)abstract
- Pseudomonas aeruginosa is a gram-negative bacterium that causes serious illnesses, particularly in immunocompromised individuals, often with a fatal outcome. The finding that the acylated homoserine lactone quorum sensing (QS) system controls the production of virulence factors in P. aeruginosa makes this system a possible target for antimicrobial therapy. It has been suggested that an N-(3-oxododecanoyl)-homoserine lactone (3O-C12-HSL) antagonist, a QS blocker (QSB), would interfere efficiently with the quorum sensing system in P. aeruginosa and thus reduce the virulence of this pathogen. In this work, a mathematical model of the QS system in P. aeruginosa has been developed. The model was used to virtually add 3O-C12-HSL antagonists that differed in their affinity for the receptor protein and for their ability to mediate degradation of the receptor. The model suggests that very small differences in these parameters for different 3O-C12-HSL antagonists can greatly affect the success of QSB based inhibition of the QS system in P. aeruginosa. Most importantly, it is proposed that the ability of the 3O-C12-HSL antagonist to mediate degradation of LasR is the core parameter for successful QSB based inhibition of the QS system in P. aeruginosa. Finally, this study demonstrates that QSBs can shift the system to a low steady state, corresponding to an uninduced state and thus, suggests that the use of 3O-C12-HSL antagonists may constitute a promising therapeutic approach against P. aeruginosa involved infections.
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| 2. |
- Frantzén, Marcus, 1981-, et al.
(författare)
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Dynamic maintenance priority of a real-world machining line
- 2016
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Ingår i: Proceedings of the 7th Swedish Production Symposium.
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Konferensbidrag (refereegranskat)abstract
- To support the shop-floor operators, decision support systems (DSS) are becoming more and more vital to the success of manufacturing systems in industry today. In order to get a DSS able to adapt to disturbances in a production system, on-line data are needed to be able to make optimal or near-optimal decisions in real-time (soft real-time). This paper investigates one part of such a system, i.e. how different priorities of maintenance activities (planned and unplanned) affect the productivity of a production system. A discrete-event simulation model has been built for a real-world machining line in order to simulate the decisions made in subject to disturbances. This paper presents a way of prioritizing operators and machines based on multiple criteria such as competence, utilization, distance, bottleneck, and Work-In-Process. An experimental study based on the real-world production system has shown promising results and given insights of how to prioritize the operators in a good way. Another novelty introduced in this paper is the use of simulation-based optimization to generate composite dispatching rules in order to find good tradeoffs when taking a decision of which machine or operator to select.
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| 3. |
- Jansson, Andreas, et al.
(författare)
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In silico simulations suggest that Th-cell development is regulated by both selective and instructive mechanisms
- 2006
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Ingår i: Immunology and Cell Biology. - : Nature Publishing Group. - 0818-9641 .- 1440-1711. ; 84:2, s. 218-226
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Tidskriftsartikel (refereegranskat)abstract
- Th-cell differentiation is highly influenced by the local cytokine environment. Although cytokines such as IL-12 and IL-4 are known to polarize the Th-cell response towards Th1 or Th2, respectively, it is not known whether these cytokines instruct the developmental fate of uncommitted Th cells or select cells that have already been committed through a stochastic process. We present an individual based model that accommodates both stochastic and deterministic processes to simulate the dynamic behaviour of selective versus instructive Th-cell development. The predictions made by each model show distinct behaviours, which are compared with experimental observations. The simulations show that the instructive model generates an exclusive Th1 or Th2 response in the absence of an external cytokine source, whereas the selective model favours coexistence of the phenotypes. A hybrid model, including both instructive and selective development, shows behaviour similar to either the selective or the instructive model dependent on the strength of activation. The hybrid model shows the closest qualitative agreement with a number of well-established experimental observations. The predictions by each model suggest that neither pure selective nor instructive Th development is likely to be functional as exclusive mechanisms in Th1/Th2 development.
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| 4. |
- Jansson, Magnus, et al.
(författare)
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Drivers of outsourcing and backsourcing in the public sector : From idealism to pragmatism
- 2020
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Ingår i: Financial Accountability and Management. - : John Wiley & Sons. - 0267-4424 .- 1468-0408. ; 37:3, s. 262-278
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Tidskriftsartikel (refereegranskat)abstract
- Local governments are bringing previously outsourced services back in-house. Research into explanations for sourcing decisions in the public sector is growing, however, few researchers have investigated drivers of both outsourcing and backsourcing in local public-governance organizations. In this study we utilize transaction cost economic theory (TCE) and political ideology to investigate underlying motives of sourcing in local public governance organizations. Based on a 2018 survey of chief financial officers (CEO) in all of Sweden's 290 municipalities, this study shows that backsourcing is strongly associated with outsourcing and that outsourcing and backsourcing should not be understood as opposite phenomena, rather as interdependent phenomena in a dynamic sourcing strategy. Outsourcing and backsourcing are driven in part by different factors: Outsourcing by political ambitions and economic factors relating to TCE, while managerial and pragmatic concerns are foregrounded for backsourcing.
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| 5. |
- Jansson, Magnus, et al.
(författare)
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Outsourcing and backsourcing in a time of crisis – experiences of double opportunism
- 2024
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Ingår i: International Review of Public Administration. - : Taylor & Francis Group. - 1229-4659 .- 2331-7795. ; 29:2, s. 102-122
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Tidskriftsartikel (refereegranskat)abstract
- This article addresses the question of how public organizations with limited capacity manage to handle large scale crises. The case analyzed in this article is the sourcing of accommodation during the migration crisis in Sweden of 2015–2016. The event was a game-changer in Swedish migration policy following a more hesitant policy than before, even though new and substantial migration crisis have followed since then. Results show how the legal framework for procurements was not adapted for extraordinary events. The Swedish state was forced to pay exaggerated prices as private contractors took advantage of the acute demand. The study develops our theoretical understanding of the sourcing process during crises and show how the short-term perspective and uncertainties that characterize crises encourage both suppliers and procurers of services to act opportunistically.
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