Accurate method for calculating currents in wires in the vicinity of curved geometries

International audiencePrecise methods to calculate currents are required for low frequency EMC simulations dealing with vehicles struck by lightning. The current model used resolves Maxwell’s equations combined with a Line model based on Holland’s thin wire formalism [1]. The challenge is related to the approximation of the source fields obtained with Yee’s scheme [2]. These sources are then used for the thin wire equations. In the vicinity of structures, the errors due to the staircase meshes representing surfaces corrupt the fields’ values. In order to bypass this issue, it was suggested to apply non structured meshes such as Finite Volume (FV) [3]. Difficulties are encountered when introducing thin oblique wires [4] in this last approach, in particular for the calculation of the local self inductance L, a numerical parameter required by the line model equations.In choosing a FV solver, difficulties will arise in terms of calculation resources due to the calculation procedure of the latter and to the unstructuredness of the meshes. To overcome this obstacle, a hybrid Non Structured-Structured (NST-ST) FV scheme which can also incorporate oblique Line models is proposed.To illustrate the advantage of this new approach, an open cylindrical structure with wires running along its walls will be taken into account. It will be illuminated by a plane wave and we shall compare the obtained results in terms of current and field values retrieved inside and also in the vicinity of the cables

Familial hypercholesterolaemia in children and adolescents from 48 countries: a cross-sectional study

Background: Approximately 450 000 children are born with familial hypercholesterolaemia worldwide every year, yet only 2·1% of adults with familial hypercholesterolaemia were diagnosed before age 18 years via current diagnostic approaches, which are derived from observations in adults. We aimed to characterise children and adolescents with heterozygous familial hypercholesterolaemia (HeFH) and understand current approaches to the identification and management of familial hypercholesterolaemia to inform future public health strategies. Methods: For this cross-sectional study, we assessed children and adolescents younger than 18 years with a clinical or genetic diagnosis of HeFH at the time of entry into the Familial Hypercholesterolaemia Studies Collaboration (FHSC) registry between Oct 1, 2015, and Jan 31, 2021. Data in the registry were collected from 55 regional or national registries in 48 countries. Diagnoses relying on self-reported history of familial hypercholesterolaemia and suspected secondary hypercholesterolaemia were excluded from the registry; people with untreated LDL cholesterol (LDL-C) of at least 13·0 mmol/L were excluded from this study. Data were assessed overall and by WHO region, World Bank country income status, age, diagnostic criteria, and index-case status. The main outcome of this study was to assess current identification and management of children and adolescents with familial hypercholesterolaemia. Findings: Of 63 093 individuals in the FHSC registry, 11 848 (18·8%) were children or adolescents younger than 18 years with HeFH and were included in this study; 5756 (50·2%) of 11 476 included individuals were female and 5720 (49·8%) were male. Sex data were missing for 372 (3·1%) of 11 848 individuals. Median age at registry entry was 9·6 years (IQR 5·8-13·2). 10 099 (89·9%) of 11 235 included individuals had a final genetically confirmed diagnosis of familial hypercholesterolaemia and 1136 (10·1%) had a clinical diagnosis. Genetically confirmed diagnosis data or clinical diagnosis data were missing for 613 (5·2%) of 11 848 individuals. Genetic diagnosis was more common in children and adolescents from high-income countries (9427 [92·4%] of 10 202) than in children and adolescents from non-high-income countries (199 [48·0%] of 415). 3414 (31·6%) of 10 804 children or adolescents were index cases. Familial-hypercholesterolaemia-related physical signs, cardiovascular risk factors, and cardiovascular disease were uncommon, but were more common in non-high-income countries. 7557 (72·4%) of 10 428 included children or adolescents were not taking lipid-lowering medication (LLM) and had a median LDL-C of 5·00 mmol/L (IQR 4·05-6·08). Compared with genetic diagnosis, the use of unadapted clinical criteria intended for use in adults and reliant on more extreme phenotypes could result in 50-75% of children and adolescents with familial hypercholesterolaemia not being identified. Interpretation: Clinical characteristics observed in adults with familial hypercholesterolaemia are uncommon in children and adolescents with familial hypercholesterolaemia, hence detection in this age group relies on measurement of LDL-C and genetic confirmation. Where genetic testing is unavailable, increased availability and use of LDL-C measurements in the first few years of life could help reduce the current gap between prevalence and detection, enabling increased use of combination LLM to reach recommended LDL-C targets early in life

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Spectral Difference method On Structured-Grids for Maxwell's Equations in Time Domain

International audienceThis article introduces a new way to discretize Maxwell's equations. It is a discontinuous highorder method based on local polynomial interpolations, named the Spectral Difference method. This approach mainly differs from the standard Discontinuous Galerkin method by solving the strong form of the equation, instead of the weak form. This article gives the main lines of the Spectral Difference method for a 1D conservation law and explains how it applies to transient Maxwell's equations. The method is then evaluated on a test-case with well-known analytical solution

Spectral Difference method On Structured-Grids for Maxwell's Equations in Time Domain

International audienceThis article introduces a new way to discretize Maxwell's equations. It is a discontinuous highorder method based on local polynomial interpolations, named the Spectral Difference method. This approach mainly differs from the standard Discontinuous Galerkin method by solving the strong form of the equation, instead of the weak form. This article gives the main lines of the Spectral Difference method for a 1D conservation law and explains how it applies to transient Maxwell's equations. The method is then evaluated on a test-case with well-known analytical solution

Oligosaccharide induced resistance in grapevine as affected by cuticle permeability

International audienceGrapevine is susceptible to many diseases such as downy mildew, caused by the oomycete Plasmopara viticola (Pv). Sulfated laminarin PS3 is obtained by chemical sulfation of laminarin, an oligosaccharide (OS) from the brown algae Laminaria digitata. PS3 has been shown to elicit plant defense reactions and to induce resistance against Pv in grapevine (1). Our aim is to understand the penetration of OS in the grapevine leaf and to correlate it with the resistance induced against Pv. For this purpose, we followed the uptake of labeled compounds in the leaf, the effect of different adjuvants on their penetration and PS3 efficacy in Pv resistance tests. 1. S. Trouvelot, A. Varnier, M. Allegre, L. Mercier, F. Baillieul, C. Arnould, V. Gianinazzi-Pearson, O. Klarzynski, J. M. Joubert, A. Pugin, X. Daire Mol Plant Microbe Interact. 21, 232-243 (2008)

Do randomized clinical trial selection criteria reflect levels of risk as observed in a general population of acute myocardial infarction survivors? The PEGASUS trial in the light of the FAST-MI 2005 registry

IF 4.638International audienceBackground: Few clinical trials have focused on populations with a history of distant myocardial infarction (MI). The PEGASUS trial assessed the impact of dual antiplatelet therapy in such patients, selected by enrichment criteria of high cardiovascular risk. Whether the PEGASUS population reflects the risk of a broader post-MI population is questionable. We analyzed whether 4-year mortality of a routine-practice population would differ according to the inclusion and exclusion criteria used in PEGASUS.Methods: FAST-MI is a nationwide French registry recruiting acute MI patients in November 2005; 2490 patients alive and without recurrent MI at one year were classified into three groups: Group 1 ("PEGASUS-like" population; n = 1395; 56%), Group 2 (population having = 1 exclusion criterion for the trial; n = 677; 27%), and group 3 (population meeting neither the PEGASUS inclusion nor exclusion criteria; n = 418, 17%).Results: Group 1 patients were older than Group 3 patients, with higher GRACE scores, more comorbidity, and less STEMI, but were younger than the PEGASUS trial population. Enrichment criteria successfully defined a population at higher risk: 4-year survival 83% in Group 1, 97% in Group 2, and 68% in Group 3 (P < 0.001). Among risk-enrichment criteria, age alone was highly discriminant: in PEGASUS-like patients, survival was 78% in those = 65 versus 94% in those <65 years.Conclusions: Enrichment criteria used in PEGAGUS succeed in defining a population at increased risk in patients with prior MI, age being the most discriminant factor. The trial population, however, was notably younger and more masculine than the corresponding real-life population in France. (C) 2016 Elsevier Ireland Ltd. All rights reserved

Biostimulation of grapevine and wheat : mode of action and possible agronomic uses

International audienc

Evidence for foliar uptake of sulfated laminarin into grapevine depending on surfactant use and leaf surface

Certains ß-1,3-glucanes, en particulier la laminarine sulfatée (PS3), sont connus pour être des inducteurs de résistance de la vigne contre l’agent pathogène Plasmopara viticola. Bien que leur efficacité soit incontestable, la protection induite reste variable au vignoble. Pour être perçue par la plante, ils nécessitent de franchir les barrières constitutives, et notamment la cuticule. Ainsi, leur faible efficacité au champ pourrait être liée par une pénétration limitée à travers la cuticule des feuilles, suite à leur pulvérisation. Dans cette étude, nous avons mis au point une méthode pour analyser les comportements de diffusion du PS3 dans les feuilles de Vitis vinifera, à l’aide d’un microscope biphotonique. Nos résultats ont révélé que ce polysaccharide est vraisemblablement capable de pénétrer à travers la cuticule des feuilles de vigne, lorsqu’il est formulé dans un adjuvant adéquat. Par ailleurs, les stomates, les parois anticlines et les trichomes se sont révélés être des zones de diffusion préférentielle pour cette molécule. Il a été intéressant de constater que son taux de pénétration était plus important sur la face abaxiale des feuilles (stomatique), que la face adaxiale (sans stomate). De plus, nous sommes parvenus à lier le taux de pénétration, avec l’efficacité de PS3 en tant qu’inducteur de résistance contre le mildiou