| 11. |
- Adare, A., et al.
(författare)
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Heavy-quark production and elliptic flow in Au plus Au collisions at root(NN)-N-S=62.4 GeV
- 2015
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 91:4
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Tidskriftsartikel (refereegranskat)abstract
- We present measurements of electrons and positrons from the semileptonic decays of heavy-flavor hadrons at midrapidity (vertical bar gamma vertical bar < 0.35) in Au + Au collisions at root(NN)-N-S = 62.4 GeV. The data were collected in 2010 by the PHENIX experiment that included the new hadron-blind detector. The invariant yield of electrons from heavy-flavor decays is measured as a function of transverse momentum in the range 1 < p(T)(e) < 5 GeV/c. The invariant yield per binary collision is slightly enhanced above the p + p reference in Au + Au 0%-20%, 20%-40%, and 40%-60% centralities at a comparable level. At this low beam energy this may be a result of the interplay between initial-state Cronin effects, final-state flow, and energy loss in medium. The v(2) of electrons from heavy-flavor decays is nonzero when averaged between 1.3 < p(T)(e) < 2.5 GeV/c for 0%-40% centrality collisions at root(NN)-N-S = 62.4 GeV. For 20%-40% centrality collisions, the v(2) at root(NN)-N-S = 62.4 GeV is smaller than that for heavy-flavor decays at root(NN)-N-S = 200 GeV. The v2 of the electrons from heavy-flavor decay at the lower beam energy is also smaller than v(2) for pions. Both results indicate that the heavy quarks interact with the medium formed in these collisions, but they may not be at the same level of thermalization with the medium as observed at root(NN)-N-S = 200 GeV.
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| 12. |
- Lossow, Stefan, 1977, et al.
(författare)
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The SPARC water vapour assessment II: Profile-to-profile comparisons of stratospheric and lower mesospheric water vapour data sets obtained from satellites
- 2019
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Ingår i: Atmospheric Measurement Techniques. - : Copernicus GmbH. - 1867-1381 .- 1867-8548. ; 12:5, s. 2693-2732
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Tidskriftsartikel (refereegranskat)abstract
- This work is distributed under the Creative Commons Attribution 4.0 License. Within the framework of the second SPARC (Stratosphere-troposphere Processes And their Role in Climate) water vapour assessment (WAVAS-II), profile-to-profile comparisons of stratospheric and lower mesospheric water vapour were performed by considering 33 data sets derived from satellite observations of 15 different instruments. These comparisons aimed to provide a picture of the typical biases and drifts in the observational database and to identify data-set-specific problems. The observational database typically exhibits the largest biases below 70 hPa, both in absolute and relative terms. The smallest biases are often found between 50 and 5 hPa. Typically, they range from 0.25 to 0.5 ppmv (5 % to 10 %) in this altitude region, based on the 50 % percentile over the different comparison results. Higher up, the biases increase with altitude overall but this general behaviour is accompanied by considerable variations. Characteristic values vary between 0.3 and 1 ppmv (4 % to 20 %). Obvious data-set-specific bias issues are found for a number of data sets. In our work we performed a drift analysis for data sets overlapping for a period of at least 36 months. This assessment shows a wide range of drifts among the different data sets that are statistically significant at the 2 σ uncertainty level. In general, the smallest drifts are found in the altitude range between about 30 and 10 hPa. Histograms considering results from all altitudes indicate the largest occurrence for drifts between 0.05 and 0.3 ppmv decade-1. Comparisons of our drift estimates to those derived from comparisons of zonal mean time series only exhibit statistically significant differences in slightly more than 3 % of the comparisons. Hence, drift estimates from profile-to-profile and zonal mean time series comparisons are largely interchangeable. As for the biases, a number of data sets exhibit prominent drift issues. In our analyses we found that the large number of MIPAS data sets included in the assessment affects our general results as well as the bias summaries we provide for the individual data sets. This is because these data sets exhibit a relative similarity with respect to the remaining data sets, despite the fact that they are based on different measurement modes and different processors implementing different retrieval choices. Because of that, we have by default considered an aggregation of the comparison results obtained from MIPAS data sets. Results without this aggregation are provided on multiple occasions to characterise the effects due to the numerous MIPAS data sets. Among other effects, they cause a reduction of the typical biases in the observational database.
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| 13. |
- Nakajima, K., et al.
(författare)
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Diagnostic accuracy of an artificial neural network compared with statistical quantitation of myocardial perfusion images: a Japanese multicenter study
- 2017
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 44:13, s. 2280-2289
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Tidskriftsartikel (refereegranskat)abstract
- Purpose Artificial neural networks (ANN) might help to diagnose coronary artery disease. This study aimed to determine whether the diagnostic accuracy of an ANN-based diagnostic system and conventional quantitation are comparable. Methods The ANN was trained to classify potentially abnormal areas as true or false based on the nuclear cardiology expert interpretation of 1001 gated stress/rest Tc-99m-MIBI images at 12 hospitals. The diagnostic accuracy of the ANN was compared with 364 expert interpretations that served as the gold standard of abnormality for the validation study. Conventional summed stress/rest/difference scores (SSS/SRS/SDS) were calculated and compared with receiver operating characteristics (ROC) analysis. Results The ANN generated a better area under the ROC curves (AUC) than SSS (0.92 vs. 0.82, p < 0.0001), indicating better identification of stress defects. The ANN also generated a better AUC than SDS (0.90 vs. 0.75, p < 0.0001) for stress-induced ischemia. The AUC for patients with old myocardial infarction based on rest defects was 0.97 (0.91 for SRS, p = 0.0061), and that for patients with and without a history of revascularization based on stress defects was 0.94 and 0.90 (p = 0.0055 and p < 0.0001 vs. SSS, respectively). The SSS/SRS/SDS steeply increased when ANN values (probability of abnormality) were > 0.80. Conclusion The ANN was diagnostically accurate in various clinical settings, including that of patients with previous myocardial infarction and coronary revascularization. The ANN could help to diagnose coronary artery disease.
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| 14. |
- Khosrawi, F., et al.
(författare)
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The SPARC water vapour assessment II: Comparison of stratospheric and lower mesospheric water vapour time series observed from satellites
- 2018
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Ingår i: Atmospheric Measurement Techniques. - : Copernicus GmbH. - 1867-1381 .- 1867-8548. ; 11:7, s. 4435-4463
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Tidskriftsartikel (refereegranskat)abstract
- Time series of stratospheric and lower mesospheric water vapour using 33 data sets from 15 different satellite instruments were compared in the framework of the second SPARC (Stratosphere-troposphere Processes And their Role in Climate) water vapour assessment (WAVAS-II). This comparison aimed to provide a comprehensive overview of the typical uncertainties in the observational database that can be considered in the future in observational and modelling studies, e.g addressing stratospheric water vapour trends. The time series comparisons are presented for the three latitude bands, the Antarctic (80°-70°S), the tropics (15°S-15°N) and the Northern Hemisphere mid-latitudes (50°-60°N) at four different altitudes (0.1, 3, 10 and 80hPa) covering the stratosphere and lower mesosphere. The combined temporal coverage of observations from the 15 satellite instruments allowed the consideration of the time period 1986-2014. In addition to the qualitative comparison of the time series, the agreement of the data sets is assessed quantitatively in the form of the spread (i.e. the difference between the maximum and minimum volume mixing ratios among the data sets), the (Pearson) correlation coefficient and the drift (i.e. linear changes of the difference between time series over time). Generally, good agreement between the time series was found in the middle stratosphere while larger differences were found in the lower mesosphere and near the tropopause. Concerning the latitude bands, the largest differences were found in the Antarctic while the best agreement was found for the tropics. From our assessment we find that most data sets can be considered in future observational and modelling studies, e.g. addressing stratospheric and lower mesospheric water vapour variability and trends, if data set specific characteristics (e.g. drift) and restrictions (e.g. temporal and spatial coverage) are taken into account.
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| 15. |
- Delegates, Global Neuroethics Summit, et al.
(författare)
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Neuroethics Questions to Guide Ethical Research in the International Brain Initiatives
- 2018
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Ingår i: Neuron. - : CELL PRESS. - 0896-6273 .- 1097-4199. ; 100:1, s. 19-36
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Forskningsöversikt (refereegranskat)abstract
- Increasingly, national governments across the globe are prioritizing investments in neuroscience. Currently, seven active or in-development national-level brain research initiatives exist, spanning four continents. Engaging with the underlying values and ethical concerns that drive brain research across cultural and continental divides is critical to future research. Culture influences what kinds of science are supported and where science can be conducted through ethical frameworks and evaluations of risk. Neuroscientists and philosophers alike have found themselves together encountering perennial questions; these questions are engaged by the field of neuroethics, related to the nature of understanding the self and identity, the existence and meaning of free will, defining the role of reason in human behavior, and more. With this Perspective article, we aim to prioritize and advance to the foreground a list of neuroethics questions for neuroscientists operating in the context of these international brain initiatives.
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