| 1. |
- Coskun, Gökhan, et al.
(author)
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Analysis of in-cylinder H2O2 and HO2 distributions in an HCCI engine - Comparison of laser-diagnostic results with CFD and SRM simulations
- 2015
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In: Combustion and Flame. - : Elsevier BV. - 0010-2180. ; 162:9, s. 3131-3139
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Journal article (peer-reviewed)abstract
- By applying a novel approach to evaluate photofragmentation laser-induced fluorescence (PFLIF) imaging, experimental quantitative information on the temporal in-cylinder distribution of hydrogen peroxide (H2O2) in a homogeneous charge compression ignition (HCCI) engine was extracted. The results from PFLIF were then compared to those obtained from chemical kinetics simulations using computational fluid dynamics (CFD) and a stochastic reactor model (SRM). For the CFD simulations, a sector mesh was applied using Reynolds-averaged Navier-Stokes (RANS) equations together with a reduced chemical kinetic model. These simulations provided detailed information on the spatial distribution of H2O2, HO2 as well as other important species and temperature. The SRM, which offers substantially reduced simulation times but no spatial information, was used with the same reduced kinetic model. Two-dimensional images from PFLIF and CFD show a fair temporal agreement, while details of the spatial distributions disagree. The CFD images show that the combustion chemistry is affected by the interaction with the cylinder walls with, for instance, a local delay of the formation and consumption of H2O2. By using probability density functions (PDFs) of H2O2 and HO2 mass fractions, comparisons could be made between experimental data and both the CFD and SRM simulations. In general the range of mass fractions show good agreement but the experimental distributions are wider. Possible reasons for this discrepancy are actual heterogeneities in the H2O2/HO2 concentration distributions not predicted by the model, spatial temperature variations, which will influence the strength of the PFLIF signal, spatial variations in the laser profiles, not accounted for in the data processing, and photon noise. The good agreement between the CFD and SRM shows the relevance of fast PDF based simulation tools. (C) 2015 The Combustion Institute. Published by Elsevier Inc. All rights reserved.
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| 3. |
- Browall, Sarah
(author)
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Molecular epidemiology of streptococcus pneumoniae
- 2015
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Doctoral thesis (other academic/artistic)abstract
- Streptococcus pneumoniae, also named pneumococci, is often part of the normal flora in the nasopharynx of healthy children. However, pneumococci are also a major cause of morbidity and mortality world-wide, and colonization is required for pneumococci to cause severe invasive diseases such as septicaemia and meningitis. By focusing on the effects of conjugated pneumococcal vaccines (PCVs) on carriage and infections caused by Streptococcus pneumoniae, this thesis aims to further the understanding of why pneumococci sometimes cause severe disease. PCVs were introduced into the childhood vaccination program in Stockholm in 2007 and replaced by PCV13 in 2010. To show the potential effect of PCVs, we collected carriage isolates and invasive pneumococcal isolates from before and after vaccine introduction, as well as clinical information about the patients. Pneumococcal isolates were characterized by molecular epidemiological typing methods such as serotyping, pulsed-field gel electrophoresis (PFGE), and multi-locus sequence typing (MLST). Before vaccine introduction serotype 6B was a dominant serotype both in carriage and invasive disease. The invasive disease potential (IDP) for serotypes and clonal types was calculated before the vaccine introduction and it was revealed that not only did the IDP differ between serotypes and clonal types, but also within clonal types as determined by MLST. Three PFGE patterns within CC138 (serotype 6B) that differed in the invasive disease potential were identified. Whole genome sequencing of four representative isolates was performed. Intra-clonal variants were found that reflected different prophage content, and major differences were observed in pneumococcal surface antigens that may affect virulence in vivo (mouse model) and invasive disease potential in children. Moreover, we found that the invasive disease potential to be lower for non-PCV13 serotypes as compared to vaccine-type strains. Patients infected with non-PCV13 strains had more often underlying diseases, and were less likely to have pneumonia. Adults tended to have a higher mortality. Furthermore, patients infected with pneumococci belonging to clonal types only expressing non-PCV13 capsules had a higher risk of septicemia and mortality. After vaccine introduction we observed that the serotype distribution changed and non-vaccine types emerged both in invasive disease and in carriage. Serotype 22F and serotype 3 were now the most commonly found serotypes causing invasive pneumococcal disease due to expansion of certain clonal types. Serotype 11A increased in asymptomatic children. In addition, serotype 11A was found to be the most common serotype in patients with lower respiratory tract infection (LRTI) in Europe. Furthermore, we found that the closely related species Streptococcus pseudopneumoniae may cause LRTI. In summary, the results presented in this thesis illuminate and clarify the need for new pneumococcal vaccines, covering more serotypes and clonal types. A universal vaccine, based on for example one or more proteins found in all clinical isolates, might eradicate all pneumococci with the potential of becoming invasive.
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| 4. |
- Proverbio, I., et al.
(author)
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The dynamics of ferromagnetic dust particles in the FTU tokamak
- 2011
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In: Plasma Physics and Controlled Fusion. - : IOP Publishing. - 0741-3335 .- 1361-6587. ; 53:11
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Journal article (peer-reviewed)abstract
- The mobilization and acceleration of metallic dust in the gap region between the last closed confinement surface and the vessel wall of the Frascati Tokamak Upgrade (FTU) is studied numerically for the definition of the appropriate location of diagnostics devoted to dust dynamics.
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| 5. |
- van Huissteden, J., et al.
(author)
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Methane emissions from permafrost thaw lakes limited by lake drainage
- 2011
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In: Nature Climate Change. - 1758-6798. ; 1:2, s. 119-123
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Journal article (peer-reviewed)abstract
- Thaw lakes in permafrost areas are sources of the strong greenhouse gas methane(1-5). They develop mostly in sedimentary lowlands with permafrost and a high excess ground ice volume, resulting in large areas covered with lakes and drained thaw-lake basins (DTLBs; refs 6,7). Their expansion is enhanced by climate warming, which boosts methane emission and contributes a positive feedback to future climate change(3,4,8). Modelling of thaw-lake growth is necessary to quantify this feedback. Here, we present a two-dimensional landscape-scale model that includes the entire life cycle of thaw lakes; initiation, expansion, drainage and eventual re-initiation. Application of our model to past and future lake expansion in northern Siberia shows that lake drainage strongly limits lake expansion, even under conditions of continuous permafrost. Our results suggest that methane emissions from thaw lakes in Siberia are an order of magnitude less alarming than previously suggested, although predicted lake expansion will still profoundly affect permafrost ecosystems and infrastructure.
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| 6. |
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| 7. |
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| 8. |
- Spong, Göran, et al.
(author)
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Mountain-and brown hare genetic polymorphisms to survey local adaptations and conservation status of the heath hare (Lepus timidus sylvaticus, Nilsson 1831)
- 2022
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In: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 9
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Journal article (peer-reviewed)abstract
- We provide the first whole genome sequences from three specimens of the mountain hare subspecies the heath hare (Lepus timidus sylvaticus), along with samples from two mountain hares (Lepus timidus timidus) and two brown hares (Lepus europaeus) from Sweden. The heath hare has a unique grey winter pelage as compared to other mountain hares (white) and brown hares (mostly brown), and face regional extinction, likely due to competitive exclusion from the non-native brown hare. Whole genome resequencing from the seven hare specimens were mapped to the Lepus timidus pseudoreference genome and used for detection of 11,363,883 polymorphic nucleotide positions. The data presented here could be useful for addressing local adaptations and conservation status of mountain hares and brown hares in Sweden, including unique subspecies.
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| 9. |
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Exporting the Public Value Test. The Regulation of Public Broadcasters’ New Media Services Across Europe
- 2011
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Editorial collection (other academic/artistic)abstract
- Public service broadcasters across Europe are venturing into the digital world, launching niche TV channels, building extensive websites, developing commercial services, entering into partnerships with external actors, and exploring new ways to reach users, whether its through smart phone apps or screens in public spaces. Such endeavours intensify fundamental discussions about what we need public service media institutions for. These are complex discussions, building on history, encompassing new technology, and involving a range of strong stakeholders. Recently, the so-called public value test has emerged as the focal point for these discussions. As a detailed regulatory scheme to measure the public worth and possible market impact of planned publicly funded media services, the public value test is causing controversy across Europe. This collection of short essays from academics, regulators, public broadcasters and private media representatives, provides thought-provoking perspectives on the state of play of public value tests in a range of European states. In so doing, the book is a topical intervention in the ongoing debate about the future of our media systems. Content: Ex Ante Tests in Europe. From Diverging Perspectives to Infinite Conclusions (Hallvard Moe & Karen Donders), In Search of the Holy Grail? Comparative Analysis in Public Broadcasting Research (Tim Raats & Caroline Pauwels), The Public Value Test. A Reasoned Response or Panic Reaction? (Karen Donders), Ex Ante Regulations, the EU and its Member States. Back to Brussels? (Ross Biggam), Public Value, the BBC and Humpty Dumpty Words – does Public Value Management Mean What it Says? (Richard Collins), The Three-step Test. Three Steps Forwards or Backwards for Public Service Broadcasting in Germany? (Irini Katsirea), The ZDF Three-step Test. A Dynamic Tool of Governance (Renate Dörr), ZDF’s Three-step Test as a Societal Debate about the Future of Public Service Broadcasting (Stoyan Radoslavov & Barbara Thomass), The Public Service Remit in Norway: What’s In and What’s Out? (Marie Therese Lilleborge), Ex Ante Limits Public Broadcasting and Gives the Public Less Attractive Services (Hilde Thoresen & Erik Boltad), Two Steps Towards a Public Value Test. Danish Public Service Broadcasting Between Two Lines of Control (Erik Nordahl Svendsen), Swedish Pre-screening of New Services. Treading Lightly (Nina Wormbs), Dutch Public Service Broadcasting Between Bureaucratic Burden and Political Choice. Implementing the Amsterdam Test in the Netherlands (Jo Bardoel & Marit Vochteloo), Publishers’ Fight for Fair Competition in the Digital Era (Herman Wolswinkel), Ex Ante Test in Flanders. Making Ends Meet? (Hilde Van den Bulck), Long Live the Ex Ante Test. The Ex Ante Test Is Dead! (Ben Appel), and Ex Ante Assessments for Public Broadcasters in Southern Europe. Delayed Europeanization? (Benedetta Brevini).
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| 10. |
- Helmersson, Sofia, et al.
(author)
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Specific effect of immunomodulatory quinoline-3-carboxamide ABR-215757 in GM-CSF stimulated bone marrow cell cultures: Block of initiation of proliferation of Gr-1(+) cells.
- 2011
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In: International Immunopharmacology. - : Elsevier BV. - 1878-1705 .- 1567-5769. ; 11, s. 1045-1051
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Journal article (peer-reviewed)abstract
- Quinoline-3-carboxamides are currently in clinical development for treatment of both autoimmune disease and cancer. Carboxamides such as ABR-215757 (5757) have shown efficacy in several in vivo mouse models of human inflammatory autoimmune disease. Some microbial infections in mice cause GM-CSF dependent accumulation of dendritic cells expressing TNFα and inducible nitric oxide synthase (iNOS; Tip-DCs) in lymphoid organs. Functionally similar DCs develop in GM-CSF stimulated bone marrow (BM) cell cultures and offered an in vitro model that allowed us to study the impact of 5757 on cellular development of relevance for in vivo inflammatory conditions. We show in here that addition of 5757 to such cultures, in a dose-dependent way increased the frequency of DCs, while it reduced the frequency of Gr-1(+) cells by inhibiting their proliferation. This effect was specific as the compound neither influenced DC development from myeloid progenitors, nor the development of granulocytes in G-CSF stimulated BM cell cultures. Importantly, we also show that 5757 treatment reduced the accumulation of Gr-1(+) cells during inflammation in vivo. We therefore propose that this compound may ameliorate autoimmune disease by blocking proliferation of Gr-1(+) cells during inflammation-induced mobilization of myeloid cells.
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