| 1. |
- Karlsson, T., et al.
(författare)
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50 forgotten Miras
- 2016
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Ingår i: Journal of the American Association of Variable Star Observers. - 0271-9053 .- 2380-3606. ; 44:2, s. 156-163
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Mattsson, Karin, et al.
(författare)
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Nanofragmentation of Expanded Polystyrene Under Simulated Environmental Weathering (Thermooxidative Degradation and Hydrodynamic Turbulence)
- 2021
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Ingår i: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Fragmentation of macroplastics into microplastics in the marine environment is probably one of the processes that have generated most drive for developing the microplastics research field. Thus, it is surprising that the level of scientific knowledge on the combinative effect of oxidative degradation and mechanical stressors on fragmentation is relatively limited. Furthermore, it has been hypothesized that plastic fragmentation continues into the nanoplastic size domains, but environmentally realistic studies are lacking. Here the effects of thermooxidative aging and hydrodynamic conditions relevant for the shoreline environment on the fragmentation of expanded polystyrene (EPS) were tested in laboratory simulations. The pre-degraded EPS was cut into pieces and subjected to mechanical, hydrodynamic simulations during four day stirring experiments. Subsamples were filtered and subsequently analyzed with light microscopy with automated image analysis particle size distribution determinations, polymer identification with Raman spectroscopy, Scanning Electron Microscopy (SEM) with automated image analysis particle size distribution. The nanoplastic size fraction was measured using nanoparticle tracking analysis. In addition, the degree of polymer oxidation was spectroscopically characterized with Fourier transform infrared (FTIR) spectroscopy. The results illustrate that fragmentation of the mesoplastic objects is observed already after 2 days, but that is more distinct after 4 days, with higher abundances for the smaller size fractions, which imply more release of smaller sizes or fragmentation in several steps. For the nanoplastic fraction, day four shows a higher abundance of released or fragmented particles than day two. The conclusions are that nanofragmentation is an important and understudied process and that standardized test protocols for both thermooxidative degradation and mechanical treatments mimicking realistic environmental conditions are needed. Further testing of the most common macroand mesoplastic materials to assess the rates and fluxes of fragmenting particles to microand nanoplastic fractions should be conducted.
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| 3. |
- Svensson, A., et al.
(författare)
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Healthcare professionals learning when implementing a digital artefact identifying patients' cognitive impairment
- 2023
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Ingår i: JOURNAL OF WORKPLACE LEARNING. - 1366-5626. ; 35:6
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Tidskriftsartikel (refereegranskat)abstract
- PurposeThis paper presents findings from a qualitative study of healthcare professionals' practice, where learning is taking place when a digital artefact is implemented for identification of patients' cognitive impairment. The use of digital artefacts is increasing in various workplaces, to include professionals in healthcare. This paper aims to explore the following research question: How is the professional learning unfolding in patient-based work when a digital artefact transforms the practice? Design/methodology/approachVarious data collection methods are used for this study, consisting of dialogue meetings, interviews and a reference-group meeting. Thematic analysis is used to inductively bring forth the themes of the collected data. FindingsProfessionals' knowledge and experience are of vital importance in learning and changing work practices. Together with their ability to reflect on changes, their knowledge and experience constitute the prefiguration when the introduction of a digital application brings about indeterminacy in the work practice. Originality/valueThis paper makes a contribution to practice-based research as it consolidates previous research and identifies professionals knowledge and learning in a healthcare context. This can be used to further explore and advance the field, as well as to establish the evidence-based importance of transforming practices based on implementation of digital artefacts.
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| 4. |
- Wallin, Gunnar B, 1936, et al.
(författare)
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Two neural mechanisms for respiration-induced cutaneous vasodilatation in humans?
- 1998
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Ingår i: The Journal of physiology. - : Wiley. - 0022-3751. ; 513 ( Pt 2), s. 559-69
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Tidskriftsartikel (refereegranskat)abstract
- 1. In humans, a deep breath is known to induce cutaneous vasoconstriction in the warm state, and vasodilatation in the cold state. To investigate whether vasodilatation in the cold state is related to reduction of sympathetic vasoconstrictor nerve traffic, we studied the effect of a deep breath on vascular resistance in a skin area on the dorsum of the hand, in which release of noradrenaline from sympathetic nerves was blocked by iontophoretic pretreatment with bretylium tosylate. Simultaneous measurements were made in two control areas. In eight healthy subjects, data were obtained from deep breaths taken before bretylium in the warm state, after general cooling to a finger skin temperature below 25 C and after rewarming to above 32 C. 2. In the warm state before bretylium pretreatment, the deep breath evoked short-lasting vasoconstrictions at all sites. In the cold state there was no change of vascular resistance in the bretylium-pretreated area, whereas in the control areas an initial tendency towards vasoconstriction was followed by a significant transient vasodilatation. After rewarming, transient vasoconstrictions reappeared at the control sites, whereas only a transient vasodilatation occurred at the bretylium-pretreated site. 3. In six healthy subjects we also monitored the effects of a deep breath on skin sympathetic nerve activity (recorded by microneurography in the peroneal nerve), and skin vascular resistance within the innervation zone of the impaled nerve fascicle in the foot. Data from thirty deep breaths per subject were averaged. 4. In the cold state, the deep breath induced a strong increase in neural discharge, followed by a transient reduction of nerve traffic lasting approximately 15 s and associated with a subsequent reduction of vascular resistance. 5. We conclude that the deep breath-induced vasodilatation in the cold state is due to reduction of sympathetic vasoconstrictor nerve traffic. The vasodilatation after bretylium treatment in the warm state raises the possibility that a deep breath induces two simultaneous neural reactions, a vasoconstrictor and an active vasodilator component, the latter being weaker and normally masked by the strong vasoconstrictor component.
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