| 1. |
- Guzzi, Nicola, et al.
(author)
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Pseudouridylation of tRNA-Derived Fragments Steers Translational Control in Stem Cells
- 2018
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In: Cell. - : Elsevier BV. - 0092-8674 .- 1097-4172. ; 173:5, s. 26-1216
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Journal article (peer-reviewed)abstract
- Pseudouridylation (Ψ) is the most abundant and widespread type of RNA epigenetic modification in living organisms; however, the biological role of Ψ remains poorly understood. Here, we show that a Ψ-driven posttranscriptional program steers translation control to impact stem cell commitment during early embryogenesis. Mechanistically, the Ψ “writer” PUS7 modifies and activates a novel network of tRNA-derived small fragments (tRFs) targeting the translation initiation complex. PUS7 inactivation in embryonic stem cells impairs tRF-mediated translation regulation, leading to increased protein biosynthesis and defective germ layer specification. Remarkably, dysregulation of this posttranscriptional regulatory circuitry impairs hematopoietic stem cell commitment and is common to aggressive subtypes of human myelodysplastic syndromes. Our findings unveil a critical function of Ψ in directing translation control in stem cells with important implications for development and disease. Translational control in stem cells is orchestrated by pseudouridylation of specific tRNA-derived fragments, impacting stem cell commitment during key developmental processes.
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| 2. |
- Hansson, Lars-Anders, et al.
(author)
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Experimental evidence for a mismatch between insect emergence and waterfowl hatching under increased spring temperatures
- 2014
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In: Ecosphere. - : Ecological Society of America. - 2150-8925 .- 2150-8925. ; 5:9, s. 120-
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Journal article (peer-reviewed)abstract
- By combining a large-scale experimental assessment on timing of insect emergence with longtermmonitoring of waterfowl hatching date, we here show that insect emergence is mainly driven bytemperature, whereas there is only a weak effect of increasing spring temperatures on inter-annualvariability in observations of waterfowl chicks. Hence, a change in timing of the mass-emergence of insectsfrom lakes and wetlands, which is the crucial food source for waterfowl chicks, will likely result in aconsumer/resource mismatch in a future climate change perspective. Specifically, we experimentally showthat a moderate increase in temperature of 38C above ambient, expected to occur within 25–75 years, leadsto a considerably (2 weeks) earlier, and more pronounced, peak in insect emergence (Chironomus sp).Moreover, by utilizing long-term Citizen Science databases, ranging over several decades, we also showthat common waterfowl species are unable to significantly adjust their reproduction to fit futuretemperature increase. Hence, based on our data we predict a future mismatch between insect emergenceand waterfowl species basing their reproduction on temperature. This will have a profound impact onreproductive success and population dynamics of many aquatic birds, as well as on freshwaterbiodiversity.
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| 3. |
- Hansson, Lena, et al.
(author)
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Ny miljö för NO-undervisning
- 2011
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In: Unga nätmiljöer. - Lund : Studentlitteratur. ; :1, s. 149-170
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Book chapter (other academic/artistic)
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| 4. |
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| 5. |
- Rönnqvist, Mikael, et al.
(author)
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Collaboration and optimization in farmland exchanges
- 2023
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In: International Transactions in Operational Research. - : John Wiley and Sons Inc. - 0969-6016 .- 1475-3995. ; 30:4, s. 1591-1616
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Journal article (peer-reviewed)abstract
- To keep businesses competitive in world markets, the number of farms in most countries is decreasing while farm size is increasing, and parcels making up the farm area are extremely fragmented. It is common for farms to expand faster than available arable land near the farm center, leading to longer distances between the farm center and field areas. Consequently, logistic costs increase and affect the farm's profitability and the environment. Moreover, there is often substantial overlap between different farms, which implies that it is possible for farmers to collaborate with each other. We developed and proposed three optimization models to describe different levels of collaboration and sharing restrictions. Many practical considerations need to be weighed, such as the soil type and crops used. We collected detailed information on farms, parcels, and cost drivers in seven large instances for our case study in Sweden. One instance had 1431 farms and 32,091 parcels with 96 crop types. The resulting optimization models were very large; special pre-processing and optimization techniques were developed for their solutions. The theoretical potential for collaboration in logistic cost reduction was very large, ranging from approximately 10% to 50% depending on the form of the collaboration. Because a large part of costs comes from less use of diesel for transport resources, the reduction in cost is directly related to a reduction in CO2 emissions. © 2022 The Authors. International Transactions in Operational Research
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| 6. |
- Sigfridsson, Kalle, et al.
(author)
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Electron transfer in ruthenium-modified spinach plastocyanin mutants
- 1998
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In: Archives of Biochemistry and Biophysics. - : Academic Press. - 0003-9861 .- 1096-0384. ; 351:2, s. 197-206
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Journal article (peer-reviewed)abstract
- Four site-directed mutants of spinach plastocyanin, Pc(Leu12His), Pc(Leu15His), Pc(Thr79His), and Pc(Lys81His), have been modified by covalent attachment of a photoactive [Ru(bpy)2(im)]2+ complex at the surface-exposed histidine residues. The Pc-Ru complexes were characterized with optical absorption, CD, and EPR spectroscopy and their spectra were found to be similar to the unmodified proteins except in the case of the Pc(Leu12His) mutant which lost the Cu ion irreversibly during the Ru modification. Electron transfer (ET) within the other Pc-Ru complexes was studied with time-resolved optical spectroscopy, using an external-quencher approach. The fully reduced [Cu(I), Ru(II)] proteins were photoexcited and subsequently oxidized by an external quencher, [Ru(NH3)6]Cl3, forming the [Cu(I), Ru(III)] proteins. This was followed by an internal ET from Cu(I) to Ru(III). The rates of the internal ET reactions exhibit an exponential dependence on metal-to-metal separation, with a decay factor of 1.1 A-1. From a temperature-dependence study of the Ru-modified Pc(Lys81His) protein, a reorganization energy for the Cu-to-Ru ET reaction of 1.2 eV was determined. In this analysis it was found necessary to include an appreciable temperature dependence in the driving force of the ET reaction.
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| 7. |
- Säll-Hansson, Karin, et al.
(author)
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The meaning of the experiences of persons with chronic pain in their encounters with the health service
- 2011
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In: Scandinavian Journal of Caring Sciences. - : Wiley. - 0283-9318 .- 1471-6712. ; 25:3, s. 444-450
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Journal article (peer-reviewed)abstract
- The meaning of the experiences of persons with chronic pain in their encounters with the health service Chronic pain causes great suffering for those affected and treating it is one of the most common assignments in the health service. The aim of the study was to investigate the meaning of the experiences of persons with chronic pain in their encounters with health service staff. The study had a descriptive design with a phenomenological approach based on the perspective of caring science. Interviews were carried out with eight patients. The study showed that patients experienced a positive approach and that the staff had understood the serious nature of the situation. A positive approach can communicate hope and help to strengthen the patient. It is important to ask the patient about how he/she experiences his/her situation and thus gain an insight into this person's lifeworld. Participation entailed being active oneself and calling attention to one's needs and wishes for treatment. The study also showed that a negative approach by the staff played a prominent part in their experiences and appeared to be engraved in their memories. A negative approach is felt as being insulting and belittling. Patients with chronic pain felt that they were discredited and that their experience of their situation was called into question. They had to fight to get care and had to suggest treatments and examinations. There were also patients who had neither been asked about their pain experience nor had the opportunity to assess their pain with an assessment scale. Some of the phases in Travelbee's relationship model could be seen in several of the encounters but not all. The participants did not always feel that the manner of the nursing staff was empathetic or sympathetic, which led to greater suffering.
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| 8. |
- Åkerholm, Mikael, et al.
(author)
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Handling Subsystems using the SaveComp Component Technology
- 2006
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In: Workshop on Models and Analysis for Automotive Systems (WMAAS'06) in conjunction with the 27th IEEE Real-Time Systems Symposium (RTSS'06), Rio de Janeiro, Brazil.
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Conference paper (peer-reviewed)
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| 9. |
- Åkerholm, Mikael, et al.
(author)
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Handling Subsystems using the SaveComp Component Technology
- 2006
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In: Proceedings of Workshop on Models and Analysis for Automotive Systems (WMAAS'06).
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Conference paper (peer-reviewed)abstract
- This article presents a component technology (SaveCCT) suitable for the development of embedded vehicular control-system software. To satisfy the requirements in the vehicular domain, SaveCCT is designed to allow analysis and verification during the entire software development process.We give an overview of SaveCCT and its associated component model SaveCCM, together with an outline of how the framework intends to support the integration of larger -- possibly independently developed -- subsystems into a complete vehicle control system.
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| 10. |
- Åkerholm, Mikael, et al.
(author)
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The SaveCCM Language Reference Manual
- 2007
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Reports (other academic/artistic)abstract
- This language reference describes the syntax and semantics of SaveCCM, acomponent modeling language for embedded systems designed with vehicle applications and safety concerns in focus. The SaveCCM component model wasdefined within the SAVE project. The SAVE components are influenced mainlyby the Rubus component technology, with a switch concept similar to thatin Koala. The semantics is defined by a transformation into timed automatawith tasks, a formalism that explicitly models timing and real-time task scheduling.The purpose of this document is to describe a semantics of the SAVE component modeling language, which can be used to describe timing and functional behavior of components. The model of a system is in some cases an over approximation of the actual system behavior. An implementation of a model can resolve non-determinism e.g. by merging tasks or assigning a scheduling policy (such as static scheduling or fixed priority, preemptive or not) that will resolvethe non-determinism.
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