1,105 research outputs found
Global turbulence simulations of the tokamak edge region with GRILLIX
Turbulent dynamics in the scrape-off layer (SOL) of magnetic fusion devices
is intermittent with large fluctuations in density and pressure. Therefore, a
model is required that allows perturbations of similar or even larger magnitude
to the time-averaged background value. The fluid-turbulence code GRILLIX is
extended to such a global model, which consistently accounts for large
variation in plasma parameters. Derived from the drift reduced Braginskii
equations, the new GRILLIX model includes electromagnetic and electron-thermal
dynamics, retains global parametric dependencies and the Boussinesq
approximation is not applied. The penalisation technique is combined with the
flux-coordinate independent (FCI) approach [F. Hariri and M. Ottaviani,
Comput.Phys.Commun. 184:2419, (2013); A. Stegmeir et al., Comput.Phys.Commun.
198:139, (2016)], which allows to study realistic diverted geometries with
X-point(s) and general boundary contours. We characterise results from
turbulence simulations and investigate the effect of geometry by comparing
simulations in circular geometry with toroidal limiter against realistic
diverted geometry at otherwise comparable parameters. Turbulence is found to be
intermittent with relative fluctuation levels of up to 40% showing that a
global description is indeed important. At the same time via direct comparison,
we find that the Boussinesq approximation has only a small quantitative impact
in a turbulent environment. In comparison to circular geometry the fluctuations
are reduced in diverted geometry, which is related to a different zonal flow
structure. Moreover, the fluctuation level has a more complex spatial
distribution in diverted geometry. Due to local magnetic shear, which differs
fundamentally in circular and diverted geometry, turbulent structures become
strongly distorted in the perpendicular direction and are eventually damped
away towards the X-point
Oral ibandronate reduces the risk of skeletal complications in breast cancer patients with metastatic bone disease: results from two randomised, placebo-controlled phase III studies
SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Are you a SCEPTIC? SoCial mEdia Precision and uTility in Conferences
We analysed Twitter feeds at an emergency medicine scientific conference to determine the (1) accuracy of disseminated educational messages and the (2) use in providing rapid feedback to speakers. Most speakers were happy for key messages to be tweeted, and the majority of tweets (34/37) represented these accurately. It is important that speakers and conference organisers consider Twitter use and its potential benefits and disadvantages
Validation of SOLPS-ITER Simulations against the TCV-X21 Reference Case
This paper presents a quantitative validation of SOLPS-ITER simulations
against the TCV-X21 reference case and provides insights into the neutral
dynamics and ionization source distribution in this scenario. TCV-X21 is a
well-diagnosed diverted L-mode sheath-limited plasma scenario in both toroidal
field directions, designed specifically for the validation of turbulence codes
[D.S. Oliveira, T. Body, et al 2022 Nucl. Fusion 62 096001]. Despite the
optimization to reduce the impact of the neutral dynamics, the absence of
neutrals in previous turbulence simulations of TCV-X21 was identified as a
possible explanation for the disagreements with the experimental data in the
divertor region. This motivates the present study with SOLPS-ITER that includes
kinetic neutral dynamics via EIRENE. Five new observables are added to the
extensive, publicly available TCV-X21 dataset. These are three deuterium Balmer
lines in the divertor and neutral pressure in the common and private flux
regions. The quantitative agreement metric is combined with the conjugate
gradient method to approach the SOLPS-ITER input parameters that return the
best overall agreement with the experiment. A proof-of-principle of this method
results in a modest improvement in the level-of-agreement; shortcomings of the
method and how to improve it are discussed. Alternatively, a scan of the
particle and heat diffusion coefficients shows an improvement of 10.4% beyond
the agreement level achieved by the gradient method. The result is found for an
increased transport coefficient compared to what is usually used for TCV L-mode
plasmas, suggesting the need for accurate self-consistent turbulence models for
predictive boundary simulations. The simulations indicate that ~65% of the
total ionization occurs in the SOL, motivating the inclusion of neutrals in
future turbulence simulations towards improved agreement with the experiment
Intravenous ibandronate reduces the incidence of skeletal complications in patients with breast cancer and bone metastases
Background: This phase III study compared the efficacy of the new potent bisphosphonate, ibandronate, with placebo as intravenous (i.v.) therapy in metastatic bone disease due to breast cancer. Patients and methods: A total of 466 patients were randomised to receive placebo (n = 158), or 2 mg (n = 154) or 6 mg (n = 154) ibandronate every 3-4 weeks for up to 2 years. The primary efficacy parameter was the number of 12-week periods with new bone complications, expressed as the skeletal morbidity period rate (SMPR). Bone pain, analgesic use and safety were evaluated monthly. Results SMPR was lower in both ibandronate groups compared with the placebo group; the difference was statistically significant for the ibandronate 6 mg group (P = 0.004 versus placebo). Consistent with the SMPR, ibandronate 6 mg significantly reduced the number of new bone events (by 38%) and increased time to first new bone event. Patients on ibandronate 6 mg also experienced decreased bone pain scores and analgesic use. Treatment with ibandronate was well tolerated. Conclusions: These results indicate that 6 mg i.v. ibandronate is effective and safe in the treatment of bone metastases from breast cance
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C-Reactive Protein Gene Variants Are Associated with Postoperative C-reactive Protein Levels After Coronary Artery Bypass Surgery
Background: Elevated baseline C-reactive protein (CRP) levels are associated with increased risk for developing cardiovascular disease. Several CRP gene variants have been associated with altered baseline CRP levels in ambulatory populations. However, the influence of CRP gene variants on CRP levels during inflammatory states, such as surgery, is largely unexplored. We describe the association between candidate CRP gene variants and postoperative plasma CRP levels in patients undergoing primary, elective coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass (CPB). Methods: Using a multicenter candidate gene association study design, we examined the association between seventeen candidate CRP single nucleotide polymorphisms (SNPs) and inferred haplotypes, and altered postoperative CRP levels in 604 patients undergoing CABG surgery with CPB. Perioperative CRP levels were measured immediately prior to surgery, post-CPB and on postoperative days (POD) 1–4. Results: CRP levels were significantly elevated at all postoperative time points when compared with preoperative levels (P < 0.0001). After adjusting for clinical covariates, the minor allele of the synonymous coding SNP, rs1800947 was associated with lower peak postoperative CRP levels () and lower CRP levels across all postoperative time points (). rs1800947 remained highly significant after Bonferroni adjustment for multiple comparisons. Conclusion: We identified a CRP gene SNP associated with lower postoperative CRP levels in patients undergoing CABG surgery with CPB. Further investigation is needed to clarify the significance of this association between CRP gene variants and the acute-phase rise in postoperative CRP levels with regard to the risk of adverse postoperative outcomes
On order and disorder during the COVID-19 pandemic
Funding: Canadian Institute for Advanced Research.In this paper, we analyse the conditions under which the COVID‐19 pandemic will lead either to social order (adherence to measures put in place by authorities to control the pandemic) or to social disorder (resistance to such measures and the emergence of open conflict). Using examples from different countries (principally the United Kingdom, the United States, and France), we first isolate three factors which determine whether people accept or reject control measures. These are the historical context of state‐public relations, the nature of leadership during the pandemic and procedural justice in the development and operation of these measures. Second, we analyse the way the crisis is policed and how forms of policing determine whether dissent will escalate into open conflict. We conclude by considering the prospects for order/disorder as the pandemic unfolds.Publisher PDFPeer reviewe
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