Josephson Coupling and Fiske Dynamics in Ferromagnetic Tunnel Junctions

We report on the fabrication of Nb/AlO_x/Pd_{0.82}Ni_{0.18}/Nb superconductor/insulator/ferromagnetic metal/superconductor (SIFS) Josephson junctions with high critical current densities, large normal resistance times area products, high quality factors, and very good spatial uniformity. For these junctions a transition from 0- to \pi-coupling is observed for a thickness d_F ~ 6 nm of the ferromagnetic Pd_{0.82}Ni_{0.18} interlayer. The magnetic field dependence of the \pi-coupled junctions demonstrates good spatial homogeneity of the tunneling barrier and ferromagnetic interlayer. Magnetic characterization shows that the Pd_{0.82}Ni_{0.18} has an out-of-plane anisotropy and large saturation magnetization, indicating negligible dead layers at the interfaces. A careful analysis of Fiske modes provides information on the junction quality factor and the relevant damping mechanisms up to about 400 GHz. Whereas losses due to quasiparticle tunneling dominate at low frequencies, the damping is dominated by the finite surface resistance of the junction electrodes at high frequencies. High quality factors of up to 30 around 200 GHz have been achieved. Our analysis shows that the fabricated junctions are promising for applications in superconducting quantum circuits or quantum tunneling experiments.Comment: 15 pages, 9 figure

Multi-ancestry genome-wide association analyses improve resolution of genes and pathways influencing lung function and chronic obstructive pulmonary disease risk.

Lung-function impairment underlies chronic obstructive pulmonary disease (COPD) and predicts mortality. In the largest multi-ancestry genome-wide association meta-analysis of lung function to date, comprising 580,869 participants, we identified 1,020 independent association signals implicating 559 genes supported by ≥2 criteria from a systematic variant-to-gene mapping framework. These genes were enriched in 29 pathways. Individual variants showed heterogeneity across ancestries, age and smoking groups, and collectively as a genetic risk score showed strong association with COPD across ancestry groups. We undertook phenome-wide association studies for selected associated variants as well as trait and pathway-specific genetic risk scores to infer possible consequences of intervening in pathways underlying lung function. We highlight new putative causal variants, genes, proteins and pathways, including those targeted by existing drugs. These findings bring us closer to understanding the mechanisms underlying lung function and COPD, and should inform functional genomics experiments and potentially future COPD therapies

Uncertainty and sensitivity analysis of the LOFT L2-5 test: Results of the BEMUSE programme

This paper presents the results and the main lessons learnt from the phase 3 of BEMUSE, an international benchmark activity sponsored by the Committee on the Safety of Nuclear Installations [CSNI: Committee on the Safety of Nuclear Installations (NEA, OECD), 2007. BEMUSE Phase III Report. NEA/CSNI R(2007) 4, October 2007] of the OECD/NEA. The phase 3 of BEMUSE aimed at performing Uncertainty and Sensitivity Analyses of thermal-hydraulic codes used for the calculation of LOFT L2-5 experiment, which simulated a Large-Break Loss-of-Coolant-Accident (LB-LOCA). Eleven participants coming from ten organisations and eight countries took part in this benchmark. In the first section of this paper, the context of BEMUSE is described as well as the methods used by the participants. In the second section, the results of the benchmark are presented. The majority of the participants find uncertainty bands which envelop the experimental data fairly well, however the width of these bands is much diverged. A synthesis of the sensitivity analysis results has been made and is expected to provide a useful basis for further uncertainty analysis dealing with LB-LOCA. Finally, recommendations are given both for uncertainty and sensitivity analysis. © 2008 Elsevier B.V. All rights reserved

Uncertainty and sensitivity analysis of the LOFT L2-5 test: Results of the BEMUSE programme

This paper presents the results and the main lessons learnt from the phase 3 of BEMUSE, an international benchmark activity sponsored by the Committee on the Safety of Nuclear Installations [CSNI: Committee on the Safety of Nuclear Installations (NEA, OECD), 2007. BEMUSE Phase III Report. NEA/CSNI R(2007) 4, October 2007] of the OECD/NEA. The phase 3 of BEMUSE aimed at performing Uncertainty and Sensitivity Analyses of thermal–hydraulic codes used for the calculation of LOFT L2-5 experiment, which simulated a Large-Break Loss-of-Coolant-Accident (LB-LOCA). Eleven participants coming from ten organisations and eight countries took part in this benchmark. In the first section of this paper, the context of BEMUSE is described as well as the methods used by the participants. In the second section, the results of the benchmark are presented. The majority of the participants find uncertainty bands which envelop the experimental data fairlywell, however the width of these bands is much diverged. A synthesis of the sensitivity analysis results has been made and is expected to provide a useful basis for further uncertainty analysis dealing with LB-LOCA. Finally, recommendations are given both for uncertainty and sensitivity analysis

Uncertainty and sensitivity analysis of a LBLOCA in a PWR Nuclear Power Plant: Results of the Phase v of the BEMUSE programme

This paper presents the results and the main lessons learnt from Phase V of BEMUSE, an international programme promoted by the Working Group on Accident Management and Analysis (GAMA) of OECD to address the issue of the capabilities of best-estimate computational tools and uncertainty analysis. The scope of Phase V is the uncertainty analysis of a Large Break Loss-Of-Coolant-Accident (LBLOCA) in a Pressurized Water Reactor. Fourteen participants from twelve organizations and ten countries participated in the Phase V of BEMUSE. The paper starts with a general description of the BEMUSE programme including the objectives, structure, and the outline of the Phase V specification. Then it summarizes some general aspects on the uncertain model parameters and the results for the uncertainty analysis and for the sensitivity evaluation. To end with, general recommendations and conclusions are presented as practical guidance for uncertainty analysis performance. © 2011 Elsevier B.V. All rights reserved

Chronic obstructive pulmonary disease and related phenotypes: Polygenic risk scores in population-based and case-control cohorts.

Background: Genetic factors influence chronic obstructive pulmonary disease (COPD) risk, but the individual variants that have been identified have small effects. We hypothesised that a polygenic risk score using additional variants would predict COPD and associated phenotypes. Methods: We constructed a polygenic risk score using a genome-wide association study of lung function (FEV1 and FEV1/forced vital capacity [FVC]) from the UK Biobank and SpiroMeta. We tested this polygenic risk score in nine cohorts of multiple ethnicities for an association with moderate-to-severe COPD (defined as FEV1/FVC <0·7 and FEV1 <80% of predicted). Associations were tested using logistic regression models, adjusting for age, sex, height, smoking pack-years, and principal components of genetic ancestry. We assessed predictive performance of models by area under the curve. In a subset of studies, we also studied quantitative and qualitative CT imaging phenotypes that reflect parenchymal and airway pathology, and patterns of reduced lung growth. Findings: The polygenic risk score was associated with COPD in European (odds ratio [OR] per SD 1·81 [95% CI 1·74–1·88] and non-European (1·42 [1·34–1·51]) populations. Compared with the first decile, the tenth decile of the polygenic risk score was associated with COPD, with an OR of 7·99 (6·56–9·72) in European ancestry and 4·83 (3·45–6·77) in non-European ancestry cohorts. The polygenic risk score was superior to previously described genetic risk scores and, when combined with clinical risk factors (ie, age, sex, and smoking pack-years), showed improved prediction for COPD compared with a model comprising clinical risk factors alone (AUC 0·80 [0·79–0·81] vs 0·76 [0·75–0·76]). The polygenic risk score was associated with CT imaging phenotypes, including wall area percent, quantitative and qualitative measures of emphysema, local histogram emphysema patterns, and destructive emphysema subtypes. The polygenic risk score was associated with a reduced lung growth pattern. Interpretation: A risk score comprised of genetic variants can identify a small subset of individuals at markedly increased risk for moderate-to-severe COPD, emphysema subtypes associated with cigarette smoking, and patterns of reduced lung growth. Funding: US National Institutes of Health, Wellcome Trust