FD-TD calculation with composite materials. Application to C160 aircraft measurements

In a frequency domain in which a material thickness is smaller than the skin depth, a formalism based on the sheet impedance concept was developed and introduced in the FD-TD (finite difference-time domain) code ALICE. The predictive capabilities of the 3D code was evaluated by comparison to analytical and experimental data. The following subject areas are covered: low frequency electromagnetic penetration of loaded apertures; FD-TD modeling; and in-flight experiment modeling

FD-TD numerical simulation of an entire lightning strike on the C160 aircraft

Experimental transient electromagnetic field measurements were performed on a Transall C160 aircraft during in-flight lightning strikes. The data allow a test of the predictive capabilities of a three dimensional time domain finite difference code (ALICE) developed at ONERA in order to investigate lightning-aircraft interactions. Using a transfer function technique in the 3D code, it is shown that a bi-leader attached to an aircraft can be simulated by a linear model, and so the electromagnetic fields can be calculated anywhere on the vehicle. Comparison of experimental and numerical results were made for several lightning strikes. Skin current density and electromagnetic field distributions are discussed in detail

A COMBINED FDTD/TLM TIME DOMAIN METHOD TO SOLVE EFFICIENTLY ELECTROMAGNETIC PROB- LEMS

Abstract—Modeling complex networks of cables inside structures and modeling disjoint objects connected by cables inside large computational domains with respect to the wavelength are two problems that currently present many difficulties. In this paper, we propose a 1D/3D hybrid method in time domain to solve efficiently these two kinds of problems. The method, based upon finite difference schemes, couples Maxwell’s equations to evaluate electromagnetic fields in 3D domains and the transmission line equations to evaluate currents and voltages on cables. Some examples are presented to show the interest of this approach. 1

Modelado de aspectos epidemiológicos de la enfermedad de Chagas

Tesis (Lic. en Física)--Universidad Nacional de Córdoba, Facultad de Matemática, Astronomía, Física y Computación, 2016.El presente trabajo final trata sobre el modelado de aspectos epidemiológicos que intervienen en la endemia chagásica. Es de especial interés comprender la compleja dinámica que resulta de la interacción entre distintas especies intervinientes, así como también los factores ambientales que conforman un hábitat especial para la expansión de la enfermedad. También se analiza el rol que cumplen los animales rurales como reservorios en la endemia, puesto que son más susceptibles al contagio que las personas. Por último, se modelan posibles estrategias preventivas a la enfermedad mediante la vacunación de animales rurales con un parásito competidor, el Trypanosoma rangeli, el cual se ha demostrado que es capaz de inducir la producción de anticuerpos en un mamífero y permitir que este último no continúe propagando el parásito.The present undergraduate project deals with the modelling of epidemiological aspects involved in Chagas endemic disease. It is of special interest to understand the complex dynamics that results from the interaction between the different implicated species, as well as the environmental factors that create a special habitat for the growth of the disease. We discuss the role that farm animals play as reservoirs in the endemic infection, since they are more susceptible than people. Finally, we model possible disease prevention strategies through the vaccination of farm animals with a competitive parasite, the Trypanosoma rangeli, which has proven to be capable of inducing the production of antibodies in a mammal that inhibits it from further propagating the parasite

Stratégie multi-méthodes dans le domaine temporel

International audienceDans cet article nous présentons une stratégie multi-méthodes pour la simulation de problèmes de CEM. Dans cette approche, nous utilisons des méthodes d'ordre élevé permettant de tenir compte de la courbure des géométries et de limiter les erreurs de dispersions et/ou de dissipation. Ces méthodes sont basées sur des schémas Galerkin Discontinu et différences finies utilisant une approximation spatiale d'ordre élevé. Enfin pour tenir compte des câbles dans les structures, nous utilisons une équation de ligne de transmission, dans le domaine temporel que nous couplons aux méthodes de calcul de champs 3D

Depression and mortality: Artifact of measurement and analysis?

Background Previous research demonstrates various associations between depression, cardiovascular disease (CVD) incidence and mortality, possibly as a result of the different methodologies used to measure depression and analyse relationships. This analysis investigated the association between depression, CVD incidence (CVDI) and mortality from CVD (MCVD), smoking related conditions (MSRC), and all causes (MALL), in a sample data set, where depression was measured using items from a validated questionnaire and using items derived from the factor analysis of a larger questionnaire, and analyses were conducted based on continuous data and grouped data. Methods Data from the PRIME Study (N=9798 men) on depression and 10-year CVD incidence and mortality were analysed using Cox proportional hazards models. Results Using continuous data, both measures of depression resulted in the emergence of positive associations between depression and mortality (MCVD, MSRC, MALL). Using grouped data, however, associations between a validated measure of depression and MCVD, and between a measure of depression derived from factor analysis and all measures of mortality were lost. Limitations Low levels of depression, low numbers of individuals with high depression and low numbers of outcome events may limit these analyses, but levels are usual for the population studied. Conclusions These data demonstrate a possible association between depression and mortality but detecting this association is dependent on the measurement used and method of analysis. Different findings based on methodology present clear problems for the elucidation and determination of relationships. The differences here argue for the use of validated scales where possible and suggest against over-reduction via factor analysis and grouping. CrownCopyright © 2013PublishedbyElsevierB.V.Allrightsreserved

294 Implementation time of a lipid lowering therapy in patients with dyslipidemia: results of Prysme study

Despite the availability of specific guidelines, the management of dyslipidemia in practice is not optimal.Objective and methodologyPRYSME, a non-interventional multicentre study carried out with 1226 general practitioners, aimed to describe the implementation time of a lipid lowering treatment according to cardiovascular risk level (primary objective) and to identify its determinants. Were eligible patients treated for a dyslipidemia diagnosed less than 2 years ago. Demographic and clinical characteristics and circumstances of diagnosis and treatment initiation were collected.Results3268 patients were included (mean age: 57 years old, males: 64%). 26% were obese and 45% overweight. Only 12% had no cardiovascular risk factors (CRF) at the time of dyslipidemia diagnosis. The most frequent CRF were arterial hypertension (50%), smoking (43%), family history of premature coronary heart disease (28%), HDL-c <0.4g/l (20%) whereas 15% of the patients had a personal history of cardiovascular disease. Dietary programs were initially implemented for 98% of the patients. More than 90% were treated with a statin. The implementation time of the treatment (evaluated according to the biological confirmation of dyslipidemia), according to the initial number of CRF, was as following:0 CRF1 CRF2 CRF≥ 3 CRFSecondary preventionTotal[-3;0] months34.3%28.6%27.1%29.3%49.1%33.1%]0;3] months23.1%26.2%26.4%24.0%21.9%23.9%> 3 months42.6%45.3%46.5%46.8%29.0%43.0%Chi-2 test : P<0.001The main determinant of an early implementation of a lipid lowering therapy (≤ 3 months) was secondary prevention (OR=1.8). The number of CRF had no significant impact.ConclusionThis study underlines the lack of awareness towards cardiovascular risk factors in the management of dyslipidemia, particularly while considering the implementation time of a lipid lowering therapy

I021 Impact du polymorphisme génétique C(-260)T du CD14 sur la pression pulsée en fonction d’autres facteurs de risque cardiovasculaires : etude populationnelle transversale à partir du registre monica

Objectif de l’étudeLe CD14 est à l’intersection entre l’inflammation, les maladies infectieuses et le syndrome métabolique. Une corrélation positive entre la concentration plasmatique du CD14 soluble (sCD14) et la rigidité aortique a été décrite dans une étude transversale. Mais différents résultats ont été retrouvés sur l’incidence des évènements cardiovasculaires en fonction du polymorphisme C(-260)T du gène du CD14.L’objectif de cette étude est d’étudier l’influence du polymorphisme C(-260)T du CD14 sur la pression pulsée et indirectement sur le risque cardiovasculaire à partir de l’étude populationnelle transversale MONICA.Déroulement de l’étude1 155 sujets âgés entre 35 et 64 ans, en prévention primaire, ont été recrutés à partir des listes électorales de la Haute Garonne entre 1995 et 1997.MéthodesLa pression pulsée brachiale était mesurée au repos à 2 reprises puis moyennée. La concentration plasmatique du sCD14 a été mesurée par méthode immunoenzymatique. La randomisation est de type mendélienne. Les sujets ont été répartis en fonction du polymorphisme C(-260)T du CD14 après génotypage : homozygotes CC, homozygotes TT ou hétérozygotes CT.RésultatsLes sujets homozygotes TT ont une pression pulsée (PP) significativement plus basse et une concentration en sCD14 significativement plus élevée. Après ajustement avec les principaux facteurs confondants (âge, sexe, facteurs de risque cardiovasculaires traités), seul le génotype du CD14 reste corrélé à la PP. Cette corrélation n’intervient qu’en présence de facteurs de risque traités. Les diabétiques traités homozygotes TT sont ceux qui bénéficient de la plus importante baisse de PP par rapport aux homozygotes diabétiques CC (− 19,4mmHg, p=0,006).ConclusionCette étude suggère que les facteurs de risque ont un impact différent sur la pression pulsée en fonction du polymorphisme C(-260)T du CD14. Cette observation pourrait contribuer à affiner le risque cardiovasculaire absolu individuel, les sujets homozygotes TT ayant un risque cardiovasculaire moindre

0191: Poor achievement of low-density lipoprotein cholesterol targets in French patients with stable coronary heart disease. Contemporary data from DYSIS II CHD study

AimWe sought to determine achievement of lipid targets according to current European guidelines (low-density lipoprotein cholesterol [LDL-C]≤70mg/dL) in patients with stable coronary heart disease (CHD) with or without lipid-lowering therapy (LLT), in the French cohort of the Dyslipidemia International Study IICHD (DYSIS IICHD).MethodsDYSIS IICHD was a multicentre observational cross-sectional study conducted from July 2013 to October 2014 in 27 centres in France. Adults with stable CHD (defined as≥1 of the following:>50% stenosis on coronary angiography or computed tomography, prior percutaneous coronary intervention, prior coronary bypass graft, history of ACS>3 months previously) and a fasting lipid profile done within the previous 12 months were consecutively enrolled. Eligible patients had to be on LLT for≥3 months or taking no LLT.ResultsA total of 436 CHD patients were enrolled. Of the 424 patients (97.2%) on LLT, 91.5% were on statin treatment at the moment of inclusion (mean±SD dose calculated in atorvastatin 27±23mg/day). Non-statin LLT was used in 17.7% patients (79.2% were on a cholesterol-absorption inhibitor). Mean±SD LDL-C was 87.4±30.5mg/dL, 28.4% achieved LDL-C<70mg/dL, and 67.7% had an LDL-C<100mg/dL (Table).Abstract 0191 – Table: Characteristics of lipid values in patients with stable CHDAll patients (n=436)LLT (n=424)No LLT (n=12)Age (years)69±1269±1274±12Men80.079.791.7ACS>3 months previously70.070.066.7Diabetes type 227.027.316.7Chronic kidney disease5.05.20Lipid variablesLDL-C (mg/dL)87.4±30.586.0±29.6135.3±24.5**LDL<70mg/dL28.429.20*Distance to target of<70mg/dL (mg/dL)31.1±24.229.7±23.265.3±24.5**LDL<100mg/dL67.769.38.3**Data are mean±SD or %.*P<0.05**P?0.0001 (LLT vs no LLT)ConclusionsThese observational data from contemporary clinical practice in France indicate suboptimal lipid control, with over two-thirds of high-risk CHD patients failing to achieve the LDL-C target despite taking LLT, and a large difference between mean value and target LDL-C. More-intensive treatment is required to optimize achievement of lipid goals in CHD