High-order discrete ordinate transport in hexagonal geometry: A new capability in ERANOS

This paper presents the implementation of an arbitrary order discontinuous Galerkin scheme within the framework of a discrete ordinate solver of the neutron transport equation for nuclear reactor calculations. More precisely, it deals with non-conforming spatial meshes for the 2D and 3D modeling of core geometries based on hexagonal assemblies. This work aims at improving the capabilities of the ERANOS code system dedicated to fast reactor analysis and design. Both the angular quadrature and spatial scheme peculiarities for hexagonal geometries are presented. A particular focus is set on the spatial non-conforming mesh and variable order capabilities of this scheme in anticipation to the development of spatial adaptiveness algorithms. These features are illustrated on a 3D numerical benchmark with comparison to a Monte Carlo reference and a 2D benchmark that shows the potential of this scheme for both h- and p-adaptation

NUMERICAL STUDY OF TIME DOMAIN APPROACH APPLIED TO PREDICTION OF NOISE RADIATION FROM ROTATING BLADES

ABSTRACT Aeroacoustic formulations in time domain are frequently used to model the aerodynamic sound of airfoils, the time data being more accessible. The formulation 1A developed by Farassat, integral solution of the Ffowcs Williams and Hawkings equation, holds great interest because of its adequacy for surfaces in arbitrary motion. The aim of this work is to study the numerical sensitivity of this model to specified parameters and the geometry used in the calculation. The numerical algorithms, spatial and time discretizations, and approximations used for far-field acoustic simulation are presented. A parametrical study of the relevant criteria is carried out based on the Isom's and Tam's test cases

Poisoning by non-edible squash: retrospective series of 353 patients from French Poison Control Centers

CONTEXT: Among the numerous varieties of squash that exist, some are edible while other bitter-tasting ones are not fit for human consumption. Cases of confusion seem to be multiplying and are characterized by digestive problems (diarrhea, vomiting, and abdominal pain). METHODS: This is a descriptive retrospective study of cases of exposure reported to French Poison Control Centers between 1 January 2012 and 12 December 2016. RESULTS: 353 patients were included, with 71.7% belonging to collective cases of poisoning. The male to female sex ratio was 0.75 for an average age of 38.2 ± 23.6 years. The circumstances of exposure were dietary for 337 patients (95.5%). The majority of the squash consumed was purchased at a store (55.8%) but some also came from the garden (25.5%). 204 patients (57.8%) mostly presented with diarrhea, vomiting, abdominal pain, sometimes with the consequent dehydration, hypotension, tachycardia, headaches, or vertigo. There were no deaths or severe (Poisoning Severity Score (PSS) 3) cases, but there were 14 patients (4.0%) of moderate severity, 190 patients (53.8%) of minor severity (PSS 1), and 149 patients (42.2%) without severity (PSS 0) but among which we include the bitter taste of the squash. The average age of PSS 2 patients was significantly (p = .003) older than that of the PSS <2 patients. CONCLUSION: As the first consequential series in Europe, our study shows that exposure to non-edible squash is frequent. Usually benign, poisoning could be the consequence of the irritating effect of certain cucurbits, the molecules responsible for the taste and toxicity of the fruits. In terms of prevention therefore, we recommend disposing of any squash with a bitter taste

Is there a difference in venous thrombosis rate in free flap anastomoses based on coupler diameter?: A systematic review. Does Size Really Matter?

Background: The adage is to use the largest anastomotic coupler device (coupler) size possible, since smaller an anastomosis might be more susceptible to thrombosis. It is unclear if this wisdom is supported by data. This study tests the hypothesis that there is no difference in the reported literature in thrombosis rate between different coupler sizes. Methods: We searched PubMed, Embase, and the Cochrane Library. After screening 235 studies, we included 11 retrospective case-series. According to the criteria of Newcastle-Ottowa Scale, quality score ranged from 2 to 4 (out of 5) and funnel plots indicated publication bias. We included a total of 5930 coupled anastomoses. We calculated thrombosis rate per coupler diameter with exact confidence intervals (CIs). We regard non-overlapping CIs as a significant difference. Results: Nine studies reported no difference in thrombosis rate based on coupler size. Two studies report a potentially greater thrombosis rates in smaller sizes: (1) 2.0 mm 27% (95% CI 17%-40%, 17/62 cases) vs. 3.0 mm 6.3% (95% CI 2.8%-12%, 8/126 cases) and (2) 1.5 mm 6.9% (95% CI 2.8%-14%, 7/101 cases) vs. 3.0 mm group 1.2% (95% CI 0.64%-2.1%, 13/1079). Conclusion: There is some evidence that suggests that smaller coupler sizes are associated with greater thrombosis rate, but the current available evidence has limitations. Performing a second anastomosis, in case, the first anastomosis is performed with a coupler size of 1.0, 1.5, or even 2.0 mm, can potentially reduce this rate, however, this remains to be determined

CDK12 globally stimulates RNA polymerase II transcription elongation and carboxyl-terminal domain phosphorylation

Cyclin-dependent kinase 12 (CDK12) phosphorylates the carboxyl-terminal domain (CTD) of RNA polymerase II (pol II) but its roles in transcription beyond the expression of DNA damage response genes remain unclear. Here, we have used TT-seq and mNET-seq to monitor the direct effects of rapid CDK12 inhibition on transcription activity and CTD phosphorylation in human cells. CDK12 inhibition causes a genome-wide defect in transcription elongation and a global reduction of CTD Ser2 and Ser5 phosphorylation. The elongation defect is explained by the loss of the elongation factors LEO1 and CDC73, part of PAF1 complex, and SPT6 from the newly-elongating pol II. Our results indicate that CDK12 is a general activator of pol II transcription elongation and indicate that it targets both Ser2 and Ser5 residues of the pol II CTD