EXPERIMENTAL STUDY OF MULTIPACTOR SUPPRESSION IN DIELECTRIC MATERIALS

International audienceA novel coaxial resonator to investigate two-surface multipactor discharges on metal and dielectric surfaces in the gap region under vacuum conditions (~10-8 mbar) has been developed and tested. The resonator is ~ 100 mm in length with an outer diameter of ~ 60 mm (internal dimensions). A pulsed RF source delivers up to 30 W average power over a wide frequency range 650-900 MHz to the RF resonator. The incident and reflected RF signals are monitored by calibrated RF diodes. An electron probe provides temporal measurements of the multipacting electron current with respect to the RF pulses. In this paper we compare and contrast the results from the RF power tests of the alumina (97.6% Al2O3) and quartz samples without a coating, “the non-coated samples” and the Alumina and quartz samples with a TiN coating in order to evaluate a home made sputtered titanium nitride (TiN) thin layers as a Multipactor suppressor. The effectiveness of this method is presented and discussed in the paper

Gestion du capital intellectuel : Le capital intellectuel dans différents domaines et ses composantes

The purpose of our article is to definethe concept of intellectual capital, to talk  about its history, its models of measurement, the components that characterize it, its impact  on organizations, and lastly how it is manifested in different fields and its relationship with  knowledge management , that is all to highlight its importance in an economy dominated by  the creation and diffusion of knowledge, since the role of intellectual capital is indelible,  especially with the increase in overall corporate investment in IC - and because of its  economic characteristics, notably its intangible nature, itss value inscreased, it also has  characteristics that are, by definition, growth-enhancing, and permit to establish evidences of  a link between investment in this intellectual capital to growth and changes in productivity.The purpose of our article is to definethe concept of intellectual capital, to talk  about its history, its models of measurement, the components that characterize it, its impact  on organizations, and lastly how it is manifested in different fields and its relationship with  knowledge management , that is all to highlight its importance in an economy dominated by  the creation and diffusion of knowledge, since the role of intellectual capital is indelible,  especially with the increase in overall corporate investment in IC - and because of its  economic characteristics, notably its intangible nature, itss value inscreased, it also has  characteristics that are, by definition, growth-enhancing, and permit to establish evidences of  a link between investment in this intellectual capital to growth and changes in productivity

Ternarno višekomponentno modeliranje adsorpcije primjenom ANN-a, LS-SVR-a i SVR-a – studija slučaja

The aim of this work was to develop three artificial intelligence-based methods to model the ternary adsorption of heavy metal ions {Pb2+, Hg2+, Cd2+, Cu2+, Zn2+, Ni2+, Cr4+} on different adsorbates {activated carbon, chitosan, Danish peat, Heilongjiang peat, carbon sunflower head, and carbon sunflower stem). Results show that support vector regression (SVR) performed slightly better, more accurate, stable, and more rapid than least-square support vector regression (LS-SVR) and artificial neural networks (ANN). The SVR model is highly recommended for estimating the ternary adsorption kinetics of a multicomponent system. This work is licensed under a Creative Commons Attribution 4.0 International License.Cilj ovog rada bio je razviti tri metode temeljene na umjetnoj inteligenciji za modeliranje trostruke adsorpcije iona teških metala {Pb2+, Hg2+, Cd2+, Cu2+, Zn2+, Ni2+, Cr4+} na različitim adsorbatima {aktivni ugljen, kitozan, danski treset, treset Heilongjiang, ugljik glave suncokreta i ugljik stabljike suncokreta). Rezultati pokazuju da se regresija potpornih vektora (SVR) pokazala nešto boljom, preciznijom, stabilnijom i bržom od regresije potpornih vektora najmanjih kvadrata (LS-SVR) i umjetnih neuronskih mreža (ANN). Za procjenu kinetike trostrukog adsorpcijskog sustava višekomponentnog sustava preporučuje se model SVR. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna

Clinical and genetic data of Huntington disease in Moroccan patients

Background: Huntington's disease (HD) occurs worldwide with prevalence varying from 0.1 to 10 /100,000 depending of the ethnic origin. Since no data is available in the Maghreb population, the aim of this study is to describe clinical and genetic characteristics of Huntington patients of Moroccan origin.Methods: Clinical and genetics data of 21 consecutive patients recruited from 2009 to 2014 from the outpatient clinic of six medical centers were analyzed. Statistical analysis was performed using descriptive statistics.Results: Twenty one patients from 17 families were diagnosed positive for the IT15 gene CAG expansion. Clinical symptoms were predominantly motor (19/21). Twelve patients had psychiatric and behavioral disorders, and 11 patients had cognitive disorders essentially of memory impairment. Analysis of genetic results showed that 5 patients had reduced penetrant (RP) alleles and 16 had fully penetrant (FP) alleles. The mean CAG repeat length in patients with RP alleles was 38.4 ± 0.54, and 45.37 ± 8.30 in FP alleles. The age of onset and the size of the CAG repeat length showed significant inverse correlation (p <0.001, r = -0.754).Conclusion: Clinical and genetic data of Moroccan patients are similar to those of Caucasian populations previously reported in the literature.Keywords: Huntington disease/diagnosis, Huntington disease/epidemiology, Huntington disease/genetics, Trinucleotide repeat expansio

Clinical and genetic data of Huntington disease in Moroccan patients

Background: Huntington's disease (HD) occurs worldwide with prevalence varying from 0.1 to 10 /100,000 depending of the ethnic origin. Since no data is available in the Maghreb population, the aim of this study is to describe clinical and genetic characteristics of Huntington patients of Moroccan origin. Methods: Clinical and genetics data of 21 consecutive patients recruited from 2009 to 2014 from the outpatient clinic of six medical centers were analyzed. Statistical analysis was performed using descriptive statistics. Results: Twenty one patients from 17 families were diagnosed positive for the IT15 gene CAG expansion. Clinical symptoms were predominantly motor (19/21). Twelve patients had psychiatric and behavioral disorders, and 11 patients had cognitive disorders essentially of memory impairment. Analysis of genetic results showed that 5 patients had reduced penetrant (RP) alleles and 16 had fully penetrant (FP) alleles. The mean CAG repeat length in patients with RP alleles was 38.4 \ub1 0.54, and 45.37 \ub1 8.30 in FP alleles. The age of onset and the size of the CAG repeat length showed significant inverse correlation (p <0.001, r = -0.754). Conclusion: Clinical and genetic data of Moroccan patients are similar to those of Caucasian populations previously reported in the literature

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

Karyological and genome size insights into cardoon (Cynara cardunculus L., Asteraceae) in Tunisia

6 pág., gráf., tablas -- Post-print del artículo publicado Caryologia. Versión revisada y corregida.This study contributes the first genome size data for wild populations of Cynara cardunculus, the presumed progenitor of artichoke and cultivated cardoon. C-values estimated by flow cytometry are 2C = 1.98–2.14(3.03) pg for wild cardoon (10 populations), 2C = 2.10–2.11 pg for cultivated cardoon (two accessions) and 2C = 2.05 pg for artichoke (one accession). Chromosome counting (carried out for all material except the artichoke) establishes diploidy in all accessions. In order to provide a phylogenetic framework for Tunisian populations, internal transcribed spacer (ITS) region was sequenced and analysed together with previously published Cynara sequences. The wild and crop cardoons present similar karyological features and genome sizes despite strong morphological differentiation, with the single exception of a Tunisian population (from Tajerouine), which exhibits a 42–53% higher genome size. Along with Sicilian individuals, Tunisian wild C. cardunculus appear genetically closer to artichoke and cardoon than to studied wild relatives from the remaining distribution. This highlights the crucial importance of taking into consideration the North African territory in deciphering the history of C. cardunculus crop domestication.This work was subsidised by the Ministerio de Educación y Ciencia, Spain (Project CGL2010-22234-C02-01 and 02/BOS) and Generalitat de Catalunya (“Ajuts a Grups de Recerca Consolidats”2009/SGR/00439). SK benefited from a grant from the Tunisian government and OH from a Juan de la Cierva postdoctoral contract from the Ministerio de Ciencia e Innovación, Spain.Peer reviewe

Learner Behavior Analysis on an Online Learning Platform

This paper introduces the study of the learners' behavior on e-learning platform to create profiles that regroup learners according to their behavior on the platform. This system can be used by the learner-agent of an intelligent tutoring system (ITS). Thus, this system will allow us to better understand the learner in a virtual learning environment to improve the learning situation by placing the learner at the center of the learning process

RF DESIGN OF A HIGH GRADIENT S-BAND TRAVELLING WAVE ACCELERATING STRUCTURE FOR THOMX LINAC

International audienceThere is growing demand from the industrial and research communities for high gradient, compact RF accelerating structures. The Thomx high gradient structure (HGS) is travelling wave (TW), quasi constant gradient section and will operate at 2998.55 MHz (30°C in vacuum)in the 2pi/3 mode. The optimization of the cell shape (Electromagnetic design) has been carried out with the codes HFSS and CST MWS, in order to improve the main RF characteristics of the cavity such as shunt impedance, accelerating gradient, group velocity, modified Poynting vector, surface fields, etc. Prototypes with a reduced number of cells have been designed. For an input power of about 20 MW, EM simulation results show that an average accelerating gradient of 28MV/m is achieved which corresponds to a peak accelerating gradient of 35 MV/m, a peak surface gradient of 44 MV/m and peak modified Poynting vector Scmax of 0.24 MW/mm2