| 1. |
- Aboushelbaya, R., et al.
(författare)
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Orbital Angular Momentum Coupling in Elastic Photon-Photon Scattering
- 2019
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Ingår i: Physical Review Letters. - 0031-9007. ; 123:11
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Tidskriftsartikel (refereegranskat)abstract
- In this Letter, we investigate the effect of orbital angular momentum (OAM) on elastic photon-photon scattering in a vacuum for the first time. We define exact solutions to the vacuum electromagnetic wave equation which carry OAM. Using those, the expected coupling between three initial waves is derived in the framework of an effective field theory based on the Euler-Heisenberg Lagrangian and shows that OAM adds a signature to the generated photons thereby greatly improving the signal-to-noise ratio. This forms the basis for a proposed high-power laser experiment utilizing quantum optics techniques to filter the generated photons based on their OAM state.
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| 2. |
- Liemohn, Michael W., et al.
(författare)
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Model Evaluation Guidelines for Geomagnetic Index Predictions
- 2018
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Ingår i: Space Weather. - 1542-7390. ; 16:12, s. 2079-2102
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Tidskriftsartikel (refereegranskat)abstract
- Geomagnetic indices are convenient quantities that distill the complicated physics of some region or aspect of near‐Earth space into a single parameter. Most of the best‐known indices are calculated from ground‐based magnetometer data sets, such as Dst, SYM‐H, Kp, AE, AL, and PC. Many models have been created that predict the values of these indices, often using solar wind measurements upstream from Earth as the input variables to the calculation. This document reviews the current state of models that predict geomagnetic indices and the methods used to assess their ability to reproduce the target index time series. These existing methods are synthesized into a baseline collection of metrics for benchmarking a new or updated geomagnetic index prediction model. These methods fall into two categories: (1) fit performance metrics such as root‐mean‐square error and mean absolute error that are applied to a time series comparison of model output and observations and (2) event detection performance metrics such as Heidke Skill Score and probability of detection that are derived from a contingency table that compares model and observation values exceeding (or not) a threshold value. A few examples of codes being used with this set of metrics are presented, and other aspects of metrics assessment best practices, limitations, and uncertainties are discussed, including several caveats to consider when using geomagnetic indices.
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| 3. |
- Rothwell, S, et al.
(författare)
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Focused HLA analysis in Caucasians with myositis identifies significant associations with autoantibody subgroups
- 2019
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Ingår i: Annals of the rheumatic diseases. - : BMJ. - 1468-2060 .- 0003-4967. ; 78:7, s. 996-1002
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Tidskriftsartikel (refereegranskat)abstract
- Idiopathic inflammatory myopathies (IIM) are a spectrum of rare autoimmune diseases characterised clinically by muscle weakness and heterogeneous systemic organ involvement. The strongest genetic risk is within the major histocompatibility complex (MHC). Since autoantibody presence defines specific clinical subgroups of IIM, we aimed to correlate serotype and genotype, to identify novel risk variants in the MHC region that co-occur with IIM autoantibodies.MethodsWe collected available autoantibody data in our cohort of 2582 Caucasian patients with IIM. High resolution human leucocyte antigen (HLA) alleles and corresponding amino acid sequences were imputed using SNP2HLA from existing genotyping data and tested for association with 12 autoantibody subgroups.ResultsWe report associations with eight autoantibodies reaching our study-wide significance level of p<2.9×10–5. Associations with the 8.1 ancestral haplotype were found with anti-Jo-1 (HLA-B*08:01, p=2.28×10–53 and HLA-DRB1*03:01, p=3.25×10–9), anti-PM/Scl (HLA-DQB1*02:01, p=1.47×10–26) and anti-cN1A autoantibodies (HLA-DRB1*03:01, p=1.40×10–11). Associations independent of this haplotype were found with anti-Mi-2 (HLA-DRB1*07:01, p=4.92×10–13) and anti-HMGCR autoantibodies (HLA-DRB1*11, p=5.09×10–6). Amino acid positions may be more strongly associated than classical HLA associations; for example with anti-Jo-1 autoantibodies and position 74 of HLA-DRB1 (p=3.47×10–64) and position 9 of HLA-B (p=7.03×10–11). We report novel genetic associations with HLA-DQB1 anti-TIF1 autoantibodies and identify haplotypes that may differ between adult-onset and juvenile-onset patients with these autoantibodies.ConclusionsThese findings provide new insights regarding the functional consequences of genetic polymorphisms within the MHC. As autoantibodies in IIM correlate with specific clinical features of disease, understanding genetic risk underlying development of autoantibody profiles has implications for future research.
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| 4. |
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| 5. |
- Karlsson, Stefan, et al.
(författare)
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Advances and Challenges of Cover Glasses for Efficient Harvesting of Solar Electricity
- 2018
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Konferensbidrag (refereegranskat)abstract
- Harvesting of solar energy through photovoltaic (PV) modules is an essential technology for increasing the share of renewable energy sources, both immediately and in the future. The glass cover material constitutes a significant part of the cost. Research and development of the cover glass is needed to increase the service lifetime and to reduce the cost per watt peak [1]. Recent research efforts in the LIMES project show that the addition of optically active components absorb harmful UV light and simultaneously convert those UV photons into visible light [2]. Thus, the profit is two-fold, increasing both service lifetime and efficiency by up to 4%. Further, the cover glass composition can be optimized to enhance the mechanical and chemical durability. It has been shown that it is possible to increase the indentation crack resistance [2] and the hydrolytic durability by three and four times respectively by modifying the glass composition. Thermal strengthening of glass for PV modules are required for mechanical durability. However, there is an increasing demand of light-weight PV modules, therefor is thermal strengthening of thin cover glass needed to meet the increasing demand. In-situ chemical vapour deposition (CVD) of Al2O3 and thermal strengthening of the cover glass provides an additionally crack resistant and chemically durable glass surface. Developments of transparent and robust multifunctional coatings that provide anti-reflective and self-cleaning properties on the outer glass surface are desired [4]. Thereby is maximal transmission and reduced soiling achieved. On the interior surface are anti-reflective and chemical barrier multifunctional coatings desirable to increase transmission and reducing potential induced degradation (PID) [5]. The LIMES concept has been demonstrated by quantitative measurements and as Si solar cells. The scale-up of the LIMES concept and additional material challenges to increase the efficiency and service lifetime will be discussed. Replacing the conventional silver strings in PV modules with transparent conductive tape and back-reflecting backsheet materials are among the promising techniques for further maximizing the efficiency.
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| 6. |
- Regardt, M, et al.
(författare)
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Patients' Experience of Myositis and Further Validation of a Myositis-specific Patient Reported Outcome Measure - Establishing Core Domains and Expanding Patient Input on Clinical Assessment in Myositis. Report from OMERACT 12
- 2015
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Ingår i: The Journal of rheumatology. - : The Journal of Rheumatology. - 0315-162X .- 1499-2752. ; 42:12, s. 2492-2495
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Tidskriftsartikel (refereegranskat)abstract
- The Outcome Measures in Rheumatology (OMERACT) myositis working group was established to examine patient-reported outcomes (PRO) as well as to validate patient-reported outcome measures (PROM) in myositis.Methods.Qualitative studies using focus group interviews and cognitive debriefing of the myositis-specific Myositis Activities Profile (MAP) were used to explore the experience of adults living with polymyositis (PM) and dermatomyositis (DM).Results.Preliminary results underscore the importance of patient input in the development of PROM to ensure content validity. Results from multicenter focus groups indicate the range of symptoms experienced including pain, fatigue, and impaired cognitive function, which are not currently assessed in myositis. Preliminary cognitive debriefing of the MAP indicated that while content was deemed relevant and important, several activities were not included; and that questionnaire construction and wording may benefit from revision. A research agenda was developed to continue work toward optimizing PRO assessment in myositis with 2 work streams. The first would continue to conduct and analyze focus groups until saturation in the thematic analysis was achieved to develop a framework that encompassed the patient-relevant aspects of myositis. The second would continue cognitive debriefing of the MAP to identify potential areas for revision. There was agreement that further work would be needed for inclusion body myositis and juvenile dermatomyositis, and that the inclusion of additional contributors such as caregivers and individuals from the pharmaceutical/regulatory spheres would be desirable.Conclusions.The currently used PROM do not assess symptoms or the effects of disease that are most important to patients; this emphasizes the necessity of patient involvement. Our work provides concrete examples for PRO identification.
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