| 1. |
- Almgren, Ellen, 1970-
(författare)
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Att fostra demokrater : Om skolan i demokratin och demokratin i skolan
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A central task for the Swedish school is to foster democratic citizens. The purpose of this thesis is to evaluate some aspects of the fostering of democrats in Swedish schools, focusing on the political knowledge of young people. For more than a decade the Swedish educational policy has considered a democratic school environment to be a fundamental right for the students. Furthermore, the school democracy is assumed to have a positive effect on the students' development of democratic competence. This assumption of a causal relationship between school democracy and political knowledge, inspired by integrative theories of democracy, is tested in this study. Another important goal for the Swedish educational policy is the equivalence of education for all students. This can be interpreted in more or less ambitious terms regarding the equality of the students' education. School segregation, however, poses a threat to any form of equivalent education. The effects of school segregation on the students' political knowledge is therefore also tested in this thesis.Using multi-level analysis on a sample of over 6000 Swedish students between 14 and 15 years of age, this study shows that a deliberative open classroom-climate has a positive effect on the students' political knowledge while the direct student influence, surprisingly, has a negative effect. Both ethnic and socioeconomic segregation have negative effects on the students political knowledge. Even more troubling, though, is the fact that the different dimensions of school democracy are related to the segregational factors. The favourable open classroom-climate is more frequent in schools where the students' parents have higher education. The counter-productive direct student influence is, on the other hand, more frequent in schools with a high number of immigrants and in schools where the students' parents have lower education. It is therefore argued that even though student influence is construed as a fundamental right, the Swedish government needs to appreciate the conflict between the goals of the educational policy: Student influence and the fostering of democrats. This conflict is especially serious since student influence in fact has a negative effect not only on the fostering of democrats but also on the equality of citizenship education.
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| 2. |
- Gustafsson, Mats, et al.
(författare)
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Inandningsbara partiklar från dubbdäcksslitage av vägbana : egenskaper och inflammatoriska effekter i mänskliga luftvägsceller. utdrag ur WearTox-projektet (VTI rapport 520)
- 2005
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The aims of this project have been to describe PM10 from studded tyre wear and to study their inflammatory effects in human airway cells. The VTI circular road simulator has been used to generate "clean" wear particles from two different pavements; asphalt concrete (ABT) and stone mastic asphalt (ABS), with granite respectively quartzite as the main stone materials. The advantage of using the road simulator is that the contribution from other sources can be minimised. During the project time, the project was expanded also to study particle generation by non-studded winter tyres (friction tyres) and two kinds of winter sanding agents, namely washed crushed stone and unwashed natural sand in combination with both studded and friction tyres. Most of these parts of the project are presented in VTI report 520. The results show that pavement wear by studded tyres generates about 40-50 times as much PM10 as that by friction tyres, but also that the ABT pavement generates several times more PM10 than the ABS pavement. The size distribution within PM10 has a maximum around 3-4 ?m and more than 95 % of the mass is larger than 1 ?m. PM10 is totally dominated by fresh stone material. A fraction of very small particles, with a number concentration peak at around 30-40 nm, was also discovered. Their origin is unknown, but since the number distribution shifted depending on which tyre type was used, a possible origin is the tyres. In the cell studies the inflammation potential of the wear particles was compared with PM10 from Hornsgatan in Stockholm and PM10 from a Stockholm subway station. Later on in the project, diesel particles were made available for comparison. The cell study results show that PM10 from the ABT pavement is at least as inflammatory as diesel particles and more inflammatory than PM10 from the subway. The PM10 from Hornsgatan generally had the highest potential, but PM10 from the ABT pavement was often in parity. This despite the fact that the Hornsgatan PM10 were the only particle sample where endotoxin could be detected. Endotoxin causes an additive effect in studies of inflammation potential. PM10 from the ABS pavement generally had a lower potential than PM10 from the ABT pavement.
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| 3. |
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| 4. |
- Gustafsson, Mats, et al.
(författare)
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Inandningsbara partiklar från interaktion mellan däck, vägbana och friktionsmaterial : slutrapport av WearTox-projektet
- 2005
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Rapport (populärvet., debatt m.m.)abstract
- The aims of this project have been to describe PM10 from studded tyre wear and to study their inflammatory effects in human airway cells. The VTI circular road simulator has been used to generate "clean" wear particles from two different pavements; asphalt concrete (ABT) and stone mastic asphalt (ABS), with granite respectively quartzite as the main stone materials. The advantage of using the road simulator is that the contribution from other sources can be minimised. During the project time, the project was expanded also to study particle generation by non-studded winter tyres (friction tyres) and two kinds of winter sanding agents, namely washed crushed stone and unwashed natural sand in combination with both studded and friction tyres. The results show that pavement wear by studded tyres generates about 40-50 times as much PM10 as that by friction tyres, but also that the ABT pavement generates several times more PM10 than the ABS pavement. The size distribution within PM10 has a maximum around 3-4 ?m and more than 95 % of the mass is larger than 1 ?m. PM10 is totally dominated by fresh stone material. A fraction of very small particles, with a number concentration peak at around 30-40 nm, was also discovered. Their origin is unknown, but since the number distribution shifted depending on which tyre type was used, a possible origin is the tyres. In the experiments using sanding material, the unwashed natural sand caused the highest PM10 concentrations. Friction tyres on natural sand caused higher concentrations than studded tyres on washed crushed stone. Studded tyres generated more PM10 than friction tyres but the difference was not as large as when no sanding material was used. In the cell studies the inflammation potential of the wear particles was compared with PM10 from Hornsgatan in Stockholm and PM10 from a Stockholm subway station. Later on in the project, diesel particles were made available for comparison. The cell study results show that PM10 from the ABT pavement is at least as inflammatory as diesel particles and more inflammatory than PM10 from the subway. The PM10 from Hornsgatan generally had the highest potential, but PM10 from the ABT pavement was often in parity. This despite the fact that the Hornsgatan PM10 were the only particle sample where endotoxin could be detected. Endotoxin causes an additive effect in studies of inflammation potential. PM10 from the ABS pavement generally had a lower potential than PM10 from the ABT pavement.
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| 5. |
- Gustafsson, Mats, et al.
(författare)
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Properties and toxicological effects of particles from the interaction between tyres, road pavement and winter traction material
- 2008
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Ingår i: Science of the Total Environment. - : Institutionen för klinisk och experimentell medicin. - 0048-9697 .- 1879-1026. ; 393:2-3, s. 226-240
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Tidskriftsartikel (refereegranskat)abstract
- In regions where studded tyres and traction material are used during winter, e.g. the Nordic countries, northern part of USA, Canada, and Japan, mechanically generated particles from traffic is the main reason for high particle concentrations in busy street- and road environments. In many Nordic municipalities the European environmental quality standard for inhalable particles (PM10) is exceeded due to these particles. In this study, particles from the wear of studded and studless friction tyres on two pavements and traction sanding were generated using a road simulator. The particles were characterized using particle sizers, PIXE and electron microscopy. Cell studies were conducted on particles sampled from the tests with studded tyres and compared with street environment, diesel exhaust and subway PM10, respectively. The results show that in the road simulator, where resuspension is minimised, studded tyres produce tens of times more particles than friction tyres. Chemical analysis of the sampled particles shows that the generated wear particles consists almost entirely of minerals from the pavement stone material, but also that S is enriched for the sub-micron particles and that Zn is enriched for friction tyres for all particles sizes. The chemical data can be used for source identification and apportionment in urban aerosol studies. A mode of ultra-fine particles was also present and is hypothesised to originate in the tyres. Further, traction material properties affect PM10 emission. The inflammatory potential of the particles from wear of pavements seems to depend on type of pavement and can be at least as potent as diesel exhaust particles. The results implies that there is a need and a good potential to reduce particle emission from pavement wear and winter time road and street operation by adjusting both studded tyre use as well as pavement and traction material properties.
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| 6. |
- Gustafsson, Mats, et al.
(författare)
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WearTox : effekter på alveolmakrofager och epitelceller av slitagepartiklar från vägbana och däck
- 2011
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Under slutet på 90-talet genomfördes mätningar av luften partikelhalter i sex svenska städer där syftet var att studera vilka halter som förekommer i gatu-, respektive taknivå och studera partiklarnas ursprung (Areskoug m. fl. 2001). Något förvånande visade det sig att den tydligt dominerande källan till partiklar i gatunivå under vinterhalvåret då halterna är som högst, inte är avgasrelaterade partiklar utan härrör från slitage av vägbana, däck och bromsar. Slitage av vägbanan orsakad av dubbdäcksanvändning bidrar mycket starkt till partikelhalterna, men även vintersandningen är en bidragande orsak. Den nyvunna kunskapen om slitagepartiklarnas betydelse för partikelhalterna kräver ökad kunskap om vilka faktorer som styr bildningen, om partiklarnas egenskaper, om deras eventuella betydelse för hälsoeffekter och om vilka åtgärder som kan bidra till att sänka bidraget.Projektet WearTox är ett av de första som Vägverket initierade för att fylla dessa kunskapsluckor. Projektet har utförts av VTI i samarbete med Lunds universitet och Linköpings universitet.Syftet med projektet har varit att studera den toxiska potentialen hos slitagepartiklar från beläggning och däck hos exponerade mänskliga luftvägsceller. slitagepartiklarnas fysikaliska, kemiska och morfologiska egenskaper. Under arbetets gång tillkom önskemål om karaktärisering av ytterligare kombinationer av däck vägbana och även från försök med sandad vägbana. Dessa tilläggsbeställningar inkluderade dock inte toxikologiska studier utan begränsade sig till karaktäriseringen av partiklarna.
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| 7. |
- Lindbom, John, 1960-, et al.
(författare)
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Exposure to wear particles generated from studded tires and pavement induces inflammatory cytokine release from human macrophages
- 2006
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Ingår i: Chemical Research in Toxicology. - : American Chemical Society (ACS). - 0893-228X .- 1520-5010. ; 19:4, s. 521-530
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Tidskriftsartikel (refereegranskat)abstract
- Health risks associated with exposure to airborne paniculate matter (PM) have been shown epidemiologically as well as experimentally, pointing to both respiratory and cardiovascular effects. Lately, wear particles generated from traffic have been recognized to be a major contributing source to the overall particle load, especially in the Nordic countries were studded tires are used. In this work, we investigated the inflammatory effect of PM10 generated from the wear of studded tires on two different types of pavement. As comparison, we also investigated PM10 from a traffic-intensive street, a subway station, and diesel exhaust particles (DEP). Human monocyte-derived macrophages, nasal epithelial cells (RPMI 2650), and bronchial epithelial cells (BEAS-2B) were exposed to the different types of particles, and the secretion of IL-6, IL-8, IL-10, and TNF-α into the culture medium was measured. The results show a significant release of cytokines from macrophages after exposure for all types of particles. When particles generated from asphalt/granite pavement were compared to asphalt/quartzite pavement, the granite pavement had a significantly higher capacity to induce the release of cytokines. The granite pavement particles induced cytokine release at the same magnitude as the street particles did, which was higher than what particles from both a subway station and DEP did. Exposure of epithelial cells to PM 10 resulted in a significant increase of TNF-α secreted from BEAS-2B cells for all types of particles used (DEP was not tested), and the highest levels were induced by subway particles. None of the particle types were able to evoke detectable cytokine release from RPMI 2650 cells. The results indicate that PM10 generated by the wear of studded tires on the street surface is a large contributor to the cytokine-releasing ability of particles in traffic-intensive areas and that the type of pavement used is important for the level of this contribution. Furthermore, the airway inflammatory potential of wear particles from tires and pavement might be of a greater magnitude than that of DEP.
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| 8. |
- Lindbom, John, 1960-, et al.
(författare)
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Wear particles generated from studded tires and pavement induces inflammatory reactions in mouse macrophage cells
- 2007
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Ingår i: Chemical Research in Toxicology. - : American Chemical Society (ACS). - 0893-228X .- 1520-5010. ; 20:6, s. 937-946
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Tidskriftsartikel (refereegranskat)abstract
- Health risks associated with exposure to airborne particulate matter (PM) have been shown epidemiologically as well as experimentally, pointing to both respiratory and cardiovascular effects. These health risks are of increasing concern in society, and to protect public health, a clarification of the toxic properties of particles from different sources is of importance. Lately, wear particles generated from traffic have been recognized as a major contributing source to the overall particle load, especially in the Nordic countries where studded tires are used. The aim of this study was to further investigate and compare the ability to induce inflammatory mediators of different traffic-related wear particles collected from an urban street, a subway station, and studded tire-pavement wear. Inflammatory effects were measured as induction of nitric oxide (NO), IL-6, TNF-α, arachidonic acid (AA), and lipid peroxidation after exposure of the murine macrophage like cell line RAW 264.7. In addition, the redox potential of the particles was measured in a cell-free system. The results show that all particles tested induce IL-6, TNF-α, and NO, and those from the urban street were the most potent ones. In contrast, particles collected from a subway station were most potent to induce lipid peroxidation, A A release, and formation of ROS. Particles from studded tire-pavement wear, generated using a road simulator, were able to induce inflammatory cytokines, NO, lipid peroxidation, and ROS formation. Interestingly, particles generated from pavement containing granite as the main stone material were more potent than those generated from pavement containing quartzite as the main stone material.
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| 9. |
- Andersson, Linda, 1973, et al.
(författare)
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Glucosylceramide synthase deficiency in the heart compromises β1-adrenergic receptor trafficking
- 2021
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Ingår i: European Heart Journal. - : Oxford University Press. - 0195-668X .- 1522-9645. ; 42:43, s. 4481-4492
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: Cardiac injury and remodelling are associated with the rearrangement of cardiac lipids. Glycosphingolipids are membrane lipids that are important for cellular structure and function, and cardiac dysfunction is a characteristic of rare monogenic diseases with defects in glycosphingolipid synthesis and turnover. However, it is not known how cardiac glycosphingolipids regulate cellular processes in the heart. The aim of this study is to determine the role of cardiac glycosphingolipids in heart function.METHODS AND RESULTS: Using human myocardial biopsies, we showed that the glycosphingolipids glucosylceramide and lactosylceramide are present at very low levels in non-ischaemic human heart with normal function and are elevated during remodelling. Similar results were observed in mouse models of cardiac remodelling. We also generated mice with cardiomyocyte-specific deficiency in Ugcg, the gene encoding glucosylceramide synthase (hUgcg-/- mice). In 9- to 10-week-old hUgcg-/- mice, contractile capacity in response to dobutamine stress was reduced. Older hUgcg-/- mice developed severe heart failure and left ventricular dilatation even under baseline conditions and died prematurely. Using RNA-seq and cell culture models, we showed defective endolysosomal retrograde trafficking and autophagy in Ugcg-deficient cardiomyocytes. We also showed that responsiveness to β-adrenergic stimulation was reduced in cardiomyocytes from hUgcg-/- mice and that Ugcg knockdown suppressed the internalization and trafficking of β1-adrenergic receptors.CONCLUSIONS: Our findings suggest that cardiac glycosphingolipids are required to maintain β-adrenergic signalling and contractile capacity in cardiomyocytes and to preserve normal heart function.
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| 10. |
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