| 1. |
- Schael, S, et al.
(författare)
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Precision electroweak measurements on the Z resonance
- 2006
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Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
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Forskningsöversikt (refereegranskat)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
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| 7. |
- Brownstein, Catherine A., et al.
(författare)
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An international effort towards developing standards for best practices in analysis, interpretation and reporting of clinical genome sequencing results in the CLARITY Challenge
- 2014
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Ingår i: Genome Biology. - : Springer Science and Business Media LLC. - 1465-6906 .- 1474-760X. ; 15:3, s. R53-
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Tidskriftsartikel (refereegranskat)abstract
- Background: There is tremendous potential for genome sequencing to improve clinical diagnosis and care once it becomes routinely accessible, but this will require formalizing research methods into clinical best practices in the areas of sequence data generation, analysis, interpretation and reporting. The CLARITY Challenge was designed to spur convergence in methods for diagnosing genetic disease starting from clinical case history and genome sequencing data. DNA samples were obtained from three families with heritable genetic disorders and genomic sequence data were donated by sequencing platform vendors. The challenge was to analyze and interpret these data with the goals of identifying disease-causing variants and reporting the findings in a clinically useful format. Participating contestant groups were solicited broadly, and an independent panel of judges evaluated their performance. Results: A total of 30 international groups were engaged. The entries reveal a general convergence of practices on most elements of the analysis and interpretation process. However, even given this commonality of approach, only two groups identified the consensus candidate variants in all disease cases, demonstrating a need for consistent fine-tuning of the generally accepted methods. There was greater diversity of the final clinical report content and in the patient consenting process, demonstrating that these areas require additional exploration and standardization. Conclusions: The CLARITY Challenge provides a comprehensive assessment of current practices for using genome sequencing to diagnose and report genetic diseases. There is remarkable convergence in bioinformatic techniques, but medical interpretation and reporting are areas that require further development by many groups.
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| 9. |
- Fattibene, P, et al.
(författare)
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The 4th international comparison on EPR dosimetry with tooth enamel Part 1: Report on the results
- 2011
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Ingår i: Radiation Measurements. - : Elsevier. - 1350-4487 .- 1879-0925. ; 46:9, s. 765-771
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents the results of the 4th International Comparison of in vitro electron paramagnetic resonance dosimetry with tooth enamel, where the performance parameters of tooth enamel dosimetry methods were compared among sixteen laboratories from all over the world. The participating laboratories were asked to determine a calibration curve with a set of tooth enamel powder samples provided by the organizers. Nine molar teeth extracted following medical indication from German donors and collected between 1997 and 2007 were prepared and irradiated at the Helmholtz Zentrum Munchen. Five out of six samples were irradiated at 0.1, 0.2, 0.5, 1.0 and 1.5 Gy air kerma; and one unirradiated sample was kept as control. The doses delivered to the individual samples were unknown to the participants, who were asked to measure each sample nine times, and to report the EPR signal response, the mass of aliquots measured, and the parameters of EPR signal acquisition and signal evaluation. Critical dose and detection limit were calculated by the organizers on the basis of the calibration-curve parameters obtained at every laboratory. For calibration curves obtained by measuring every calibration sample three times, the mean value of the detection limit was 205 mGy, ranging from 56 to 649 mGy. The participants were also invited to provide the signal response and the nominal dose of their current dose calibration curve (wherever available), the critical dose and detection limit of which were also calculated by the organizers.
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| 13. |
- Pietersz, R. N. I., et al.
(författare)
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Prophylactic platelet transfusions
- 2012
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Ingår i: Vox Sanguinis. - : Wiley. - 0042-9007 .- 1423-0410. ; 103:2, s. 159-176
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Tidskriftsartikel (refereegranskat)
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| 15. |
- Fahlstedt, Madelen, 1983-, et al.
(författare)
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Ranking and Rating Bicycle Helmet Safety Performance in Oblique Impacts Using Eight Different Brain Injury Models
- 2021
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Ingår i: Annals of Biomedical Engineering. - : Springer. - 0090-6964 .- 1573-9686.
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Tidskriftsartikel (refereegranskat)abstract
- Bicycle helmets are shown to offer protection against head injuries. Rating methods and test standards are used to evaluate different helmet designs and safety performance. Both strain-based injury criteria obtained from finite element brain injury models and metrics derived from global kinematic responses can be used to evaluate helmet safety performance. Little is known about how different injury models or injury metrics would rank and rate different helmets. The objective of this study was to determine how eight brain models and eight metrics based on global kinematics rank and rate a large number of bicycle helmets (n=17) subjected to oblique impacts. The results showed that the ranking and rating are influenced by the choice of model and metric. Kendall’s tau varied between 0.50 and 0.95 when the ranking was based on maximum principal strain from brain models. One specific helmet was rated as 2-star when using one brain model but as 4-star by another model. This could cause confusion for consumers rather than inform them of the relative safety performance of a helmet. Therefore, we suggest that the biomechanics community should create a norm or recommendation for future ranking and rating methods.
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| 16. |
- Hemdal, Bengt, et al.
(författare)
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Clinical evaluation of a new set of image quality criteria for mammography.
- 2005
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Ingår i: Radiation protection dosimetry. - : Oxford University Press (OUP). - 0144-8420 .- 1742-3406. ; 114:1-3, s. 389-94
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Tidskriftsartikel (refereegranskat)abstract
- The European Commission (EC) quality criteria for screen-film mammography are used as a tool to assess image quality. A new set of criteria was developed and initially tested in a previous study. In the present study, these criteria are further evaluated using screen-film mammograms that have been digitised, manipulated to simulate different image quality levels and reprinted on film. Expert radiologists have evaluated these manipulated images using both the original (EC) and the new criteria. A comparison of three different simulated dose levels reveals that the new criteria yield a larger separation of image criteria scores than the old ones. These results indicate that the new set of image quality criteria has a higher discriminative power than the old set and thus seems to be more suitable for evaluation of image quality in mammography.
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| 17. |
- Ji, S., et al.
(författare)
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Use of Brain Biomechanical Models for Monitoring Impact Exposure in Contact Sports
- 2022
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Ingår i: Annals of Biomedical Engineering. - : Springer Nature. - 0090-6964 .- 1573-9686. ; 50:11, s. 1389-1408
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Tidskriftsartikel (refereegranskat)abstract
- Head acceleration measurement sensors are now widely deployed in the field to monitor head kinematic exposure in contact sports. The wealth of impact kinematics data provides valuable, yet challenging, opportunities to study the biomechanical basis of mild traumatic brain injury (mTBI) and subconcussive kinematic exposure. Head impact kinematics are translated into brain mechanical responses through physics-based computational simulations using validated brain models to study the mechanisms of injury. First, this article reviews representative legacy and contemporary brain biomechanical models primarily used for blunt impact simulation. Then, it summarizes perspectives regarding the development and validation of these models, and discusses how simulation results can be interpreted to facilitate injury risk assessment and head acceleration exposure monitoring in the context of contact sports. Recommendations and consensus statements are presented on the use of validated brain models in conjunction with kinematic sensor data to understand the biomechanics of mTBI and subconcussion. Mainly, there is general consensus that validated brain models have strong potential to improve injury prediction and interpretation of subconcussive kinematic exposure over global head kinematics alone. Nevertheless, a major roadblock to this capability is the lack of sufficient data encompassing different sports, sex, age and other factors. The authors recommend further integration of sensor data and simulations with modern data science techniques to generate large datasets of exposures and predicted brain responses along with associated clinical findings. These efforts are anticipated to help better understand the biomechanical basis of mTBI and improve the effectiveness in monitoring kinematic exposure in contact sports for risk and injury mitigation purposes.
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| 18. |
- Lanhede, B., et al.
(författare)
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The Influence of Different Technique Factors on Image Quality for Chest Radiographs: Application of the Recent CEC Image Quality Criteria
- 2000
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Ingår i: Radiation Protection Dosimetry. - 1742-3406. ; 90:1-2, s. 203-206
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the first this work part of the EU-project, Trial I, was to evaluate and possibly improve the CEC image criteria for radiographic chest images. Chest images of healthy volunteers were acquired using different technique factors. The image criteria were used as a tool to discriminate between the different images. The technique factors were chosen so that the image quality would differ slightly. Four different technique parameters, each with two possible settings, used in clinical practice today, were used: tube voltage - 102 and 141 kV; screen/film speed - 160 and 320; maximum optical density in the parenchyma - 1.3 and 1.8; method for scatter reduction - air gap 30/390 and moving grid40/12. The results showed that the image criteria were able to separate between different technique groups. Some conclusions can be drawn from the results Optical density 1.8 was better than 1.3 independent of the other parameters. . Among the six combinations ranked best , four used tube voltage 141 kV and four used air gap technique for scatter reduction. No difference was seen for screen/film speed. No correlation was seen between the ranking of the systems and patient dose.
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| 19. |
- Luederitz, Christopher, et al.
(författare)
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A review of urban ecosystem services: six key challenges for future research
- 2015
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Ingår i: Ecosystem Services. - : Elsevier BV. - 2212-0416. ; 14, s. 98-112
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Forskningsöversikt (refereegranskat)abstract
- Global urbanization creates opportunities and challenges for humanwell-being and transition towards sustainability. Urban areas are human-environment systems that depend fundamentally on ecosystems, and thus require an understanding of the management of urban ecosystem services to ensure sustainable urban planning. The purpose of this study is to provid easy stematic review of urban ecosystem sservices research, which addresses the combined domain of ecosystem services and urban development. We examined emerging trends and gaps in how urban ecosystem services are conceptualized in peer-reviewed case study literature, including the geographical distribution ofresearch,the development and use of the urban ecosystem services concept,and thei nvolvement of stakeholders. We highlight six challenges aimed at strengthening the concept's potential to facilitate meaningful inter-and transdis ciplinary work for ecosystem services research and planning. Achieving a cohesive conceptual approach in ther esearch field will address(i)the need for more extensive spatial and contextual coverage,(ii) continual clarification of definitions, (iii)recognition of limited datat ransferability,(iv)more comprehensive stakeholder involvement,(v)more integrated research efforts,and(vi)translation of scientific findings into actionable knowledge,feeding information back into planning and management.We conclude with recommendations for conducting further research while incorporating these challenges.
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| 20. |
- Panzer, Matthew B., et al.
(författare)
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NUMERICAL CROWDSOURCING OF NFL FOOTBALL HELMETS
- 2018
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert. - 0897-7151 .- 1557-9042. ; 35:16, s. A148-A148
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 22. |
- Tadokoro, K., et al.
(författare)
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Problems with irradiators
- 2010
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Ingår i: Vox Sanguinis. - : Wiley. - 0042-9007 .- 1423-0410. ; 98:1, s. 78-84
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Tidskriftsartikel (refereegranskat)
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| 23. |
- Tingberg, Anders, et al.
(författare)
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The influence of the characteristic curve on the clinical image quality and patient absorbed dose in lumbar spine radiography
- 2001
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Ingår i: Proceedings of SPIE. - : SPIE. - 0819440108 ; 4324, s. 41503-41503
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Konferensbidrag (refereegranskat)abstract
- The 'European Guidelines on Quality Criteria for Diagnostic Radiographic Images' do not address the choice of film characteristic (H/D) curve, which is an important parameter for the description of a radiographic screen-film system. Since it is not possible to investigate this influence by taking repeated exposures of the same patients on films with systematically varied H/D curves, patient images of lumbar spine were digitised in the current study. The image contrast was altered by digital image processing techniques, simulating images with H/D curves varying from flat over standard latitude to a film type steeper than a mammography film. The manipulated images were printed on film for evaluation. Seven European radiologists evaluated the clinical image quality of in total 224 images by analysing the fulfilment of the European Image Criteria and by visual grading analysis of the images. The results show that the local quality can be significantly improved by the application of films with a steeper film H/D curve compared to the standard latitude film. For images with an average optical density of about 1.25, the application of the steeper film results in a reduction of patient absorbed dose by about 10-15% without a loss of diagnostically relevant image information. The results also show that the patient absorbed dose reduction obtained by altering the tube voltage from 70 kV to 90 kV coincides with a loss of image information that cannot be compensated for by simply changing the shape of the H/D curve.
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| 24. |
- Tingberg, Anders, et al.
(författare)
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What is worse: Decreased spatial resolution or increased noise?
- 2002
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Ingår i: Proceedings of SPIE. - : SPIE. - 9780819444318 ; 4686, s. 338-346
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Konferensbidrag (refereegranskat)abstract
- Purpose: To investigate the relative importance of spatial resolution and noise on the image quality of clinical radiographs. Methods: The spatial resolution and noise of fifteen digitised lumbar spine radiographs were altered with image processing. Three different MTF curves and three different Wiener spectra were combined into seven different combinations of spatial resolution and noise. These seven combinations were applied to the original data set, and the resulting images were printed on film. Seven expert radiologists evaluated the clinical image quality of the resulting images with visual grading analysis (VGA) of structures based on the European Image Criteria. Results: The results show that added noise is more deteriorating than reduced spatial resolution for the clinical image quality. For a given MTF and noise level, the worst was the one with increased noise followed by the one with both reduced MTF and added noise (mimicking a faster screen-film combination). Reduced MTF only gave the highest rating. Conclusions: It is more important to find methods for removing noise than to try to improve the MTF of a radiographic system. A noisy image can sometimes be improved by reducing the spatial resolution.
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