Antenna Modeling Based on a Multiple Spherical Wave Expansion Method: Application to an Antenna Array

WOSInternational audienceA method to derive an equivalent radiation source for planar antennas is presented. This method is based on spherical near-field (NF) data (measured or computed) to ascertain an equivalent set of infinitesimal dipoles placed over the main antenna aperture. These produce the same antenna radiation field, both inside and outside the minimum sphere enclosing the antenna. A spherical wave expansion (SWE) of the NF data is written in terms of infinitesimal dipoles using a transition matrix. This matrix expresses the linear relations between the transmission coefficients of the antenna and the transmission coefficients of each dipole. The antenna a priori information are used to set the spatial distribution of the equivalent dipoles. The translational and rotational addition theorems are exploited to derive the transmission coefficients of the dipoles. Once the excitation of each dipole is known, the field at any aspect angle and distance from the antenna is rapidly calculated. Computations with EM simulation data of an antenna array illustrate the reliability of the method

The use of infinitesimal dipoles and the spherical wave expansion for planar antennas modeling

International audienceIn this paper, a method to derive an equivalent radiation model for planar antennas is presented. This method uses the spherical near-field (NF) data (measured or computed) to ascertain an equivalent set of infinitesimal dipoles placed over the main antenna surface. The spherical wave expansion (SWE) of the NF data is written in terms of infinitesimal dipoles using a transition matrix. This matrix expresses the linear relations between the spherical wave coefficients of the antenna and the spherical wave coefficients of each dipole. Once the excitation of each dipole is known, the field at any angle and distance from the antenna is rapidly calculated even inside the minimum sphere. Computations with EM simulation data of an antenna array illustrate the reliability of the method

A Graph-based approach to derive the geodesic distance on Statistical manifolds: Application to Multimedia Information Retrieval

In this paper, we leverage the properties of non-Euclidean Geometry to define the Geodesic distance (GD) on the space of statistical manifolds. The Geodesic distance is a real and intuitive similarity measure that is a good alternative to the purely statistical and extensively used Kullback-Leibler divergence (KLD). Despite the effectiveness of the GD, a closed-form does not exist for many manifolds, since the geodesic equations are hard to solve. This explains that the major studies have been content to use numerical approximations. Nevertheless, most of those do not take account of the manifold properties, which leads to a loss of information and thus to low performances. We propose an approximation of the Geodesic distance through a graph-based method. This latter permits to well represent the structure of the statistical manifold, and respects its geometrical properties. Our main aim is to compare the graph-based approximation to the state of the art approximations. Thus, the proposed approach is evaluated for two statistical manifolds, namely the Weibull manifold and the Gamma manifold, considering the Content-Based Texture Retrieval application on different databases

Mirror Movements and Myelomeningocele: Report of A Single Case and Review of Literature

How to Cite This Article: IIbtihel Rébai I, Benrhouma H, Kraoua I, Drissi C, Ben Hammouda M, Gouider-khouja N. Mirror Movements and Myelomeningocele: Report of A Single Case and Review of Literature. Iran J Child Neurol. 2013 Summer;7(3):58-61. ObjectiveMirror movements (MM) have been described in several pathological conditions. Their association with neural tube defects is rare, and only 5 cases have been reported in literature to date. We report on a case of MM associated with cervical myelomeningocele, and we discuss the diffusion tensor imaging findings and the underlying mechanism. References1. Cohen LG, Meer J, Tarkka I, Bierner S, Leiderman DB,Dubinsky RM, et al. Congenital Mirror Movements. Abnormal organization of motor pathways in two patients. Brain 1991;114(Pt 1B):381-403.2. Rasmussen P. Persistent mirror movements: a clinicalstudy of 17 children, adolescents and young adults. DevMed Child Neurol 1993;35(8):699-707.3. Forget R, Boghen D, Attig E, Lamarre Y. Electromyographicstudies of congenital mirror movements. Neurology 1986;36(10):1316-22.4. Erdincler P. Cervical cord tethering and congenital mirrormovements: is it an association rather than a coincidence?Br J Neurosurg 2002;16(5):519–22.5. Odabasi Z, Gökçil Z, Kütükçü Y, Vural O, Yardim M.Mirror movements associated with cervical meningocele:case report. Minim Invas Neurosurg 1998;41(2):99–100.6. Erol FS, Topsakal C, Ozveren MF, Akdemir I, CobanogluB. Meningocele with cervical dermoid sinus tract presenting with congenital mirror movement and recurrent meningitis. Yonsei Med J 2004;45(3):568–72.7. Andrabi Y, Nejat F, El Khashab, Ashrafi MR. Mirror movement associated with neural tube defects. Neuropsychiatr Dis Treat 2008;4(6):1273–76.8. Avery LW, Rentfro CC. The Klippel–Feil syndrome. A pathological report. Arch Neurol Psychiat 1936;36:1068- 76.9. Gunderson CH, Solitaire GB. Mirror movements in patients with Klippel–Feil syndrome. Arch Neurol 1968;18(6):675–9.10. Tuch DS, Reese TG, Wiegell MR, Makris N, Belliveau JW, Wedeen VJ. High angular resolution diffusion imaging reveals intravoxel white matter fiber heterogeneity. Magn Reson Med 2002;48(4):577-82.11. Mamata H, Mamata Y, Westin CF, Shenton ME, Kikinis R, Jolesz FA, et al. High-resolution line scan diffusion tensor MR imaging of white matter fiber tract anatomy. AJNR Am J Neuroradiol 2002;23(1):67-75.12. Galléa C, Popa T, Billot S, Méneret A, Depienne C, RozeE. Congenital mirror movements: a clue to understandingbimanual motor control. J Neurol 2011;258(11):1911-9.

Peri-partum cardiomyopathy in a pregnant woman at term revealed by acute pulmonary edema: what to do in front this catastrophic situation?

Peripartum Cardiomyopathy is insufficient congestive heart occurring in the last month of pregnancy and 5  months after delivery, in the absence of preexisting heart disease and identified etiology. This heart disease is associated with echocardiography systolic dysfunction and left ventricular dilatation. Its incidence ranges from 1/3000 to 1/15000, depending on the region, including much higher in some African countries, it particularlyconcern women over 30 years, multiparous and multiple pregnancies. The pathogenesis remains unclear, the prognosis is closely related to the complete recovery of cardiac function. We report through the clinical case of a woman aged 33 years admitted to the ICU for acute pulmonary edema of sudden onset of a term pregnancy and what to do before this critical situationKey words: Peri-partum, cardiomyopathy, acute pulmonary edem

Highly virulent strains of the avian infectious bursal disease virus: Literature review and epidemiological situation

Cette revue se focalise sur le virus très virulent de la bursite infectieuse aviaire (vvIBDV). Ce virus est présent dans le monde entier, causant des pertes économiques considérables représentant une menace pour l'industrie de la volaille. L’émergence des formes aiguës de la maladie a radicalement changé l’épidémiologie de l’IBD. Bien que leur origine soit encore à l’étude, les vvIBDV se sont répandus dans le monde entier de manière explosive mais conservée. Cela pose la question de l’origine des vvIBDV, de la possibilité d’existence de réservoirs et de l'émergence possible de nouvelles lignées distinctes dans l’avenir. Il est devenu évident que les acides aminés dans la région hyper-variable de la protéine virale VP2 constitue une base moléculaire de la variation antigénique, mais aucune mutation qui détermine la pathogénicité n’a été identifiée. Ces marqueurs moléculaires des souches vvIBDV doivent être considérés davantage comme une évolution commune plutôt que marqueurs de virulence. Le seul critère valable pour la classification des souches d’IBDV en tant que «pathotype» doit faire référence à leur virulence clinique. Cet article présente une synthèse des caractéristiques moléculaires, phylogénétiques, épidémiologiques, antigéniques et pathotypiques des souches très virulentes du virus de la bursite infectieuse aviaire. Mots clés: Revue bibliographique, vvIBDV, moléculaire, épidémiologie, phylogénie, pathotypeThis review focuses on the very virulent viral avian infectious bursal disease virus (vvIBDV). This virus was first described in the United States about 30 years ago, it quickly spread around the world, causing considerable economic losses; after three decades, it still poses a threat to the poultry industry. The emergence of acute forms of the disease has radically changed the epidemiology of IBD. Although their origin is still under study, vvIBDV has spread throughout the world in an explosive but conservative manner. This raises the question of the origin of vvIBDV, the possibility of existence of reservoirs and the possible emergence of new distinct lineages in the future. It has become clear that the amino acids in the hyper-variable region of the VP2 viral protein constitute a molecular basis for antigenic variation, but no mutation that determines pathogenicity has been identified. These molecular markers of the vvIBDV strains should be considered more as a common evolution than as markers of virulence. This article presents a synthesis of the molecular, phylogenetic, epidemiological, antigenic and pathotypic characteristics of the very virulent strains of IBDV. Keywords: Review, vvIBDV, molecular, phylogeny, epidemiology, pathotype

Anesthesia for endoscopic retrograde cholangiopancreatography: target-controlled infusion versus standard volatile anesthesia

Abstract Background Endoscopic retrograde cholangiopancreatography (ERCP) is a technique used both for diagnosis and for the treatment of biliary and pancreatic diseases. ERCP has some anesthetic implications and specifi c complications. Th e primary outcome aim was to compare two protocols in terms of time of extubation. We also compared anesthetic protocols in terms of hemodynamic and respiratory instability, antispasmodics needs, endoscopist satisfaction, and recovery room stay

Zootechnical performance study and susceptibility to Avian Influenza virus H9N2 in a breed of crossbred chicken with intermediate growth

La viande de volaille constitue la protéine d’origine animale la plus consommée en raison de son prix abordable par rapport aux autres denrées animales. De ce fait, le secteur avicole connait constamment des progrès améliorant la productivité et la qualité organoleptique des viandes de volaille.  Pour satisfaire aux enjeux de la sécurité alimentaire et l’exigence des citoyens et consommateurs, le présent travail consiste à étudier et comparer les performances zootechniques ainsi que la sensibilité au virus H9N2 de poulet croisé à croissance intermédiaire (I), par rapport à deux races de poulets à croissance rapide (R) et à croissance lente (L). Les résultats de l’étude ont montré des performances zootechniques de la race I à croissance intermédiaire similaire à celles du poulet à croissance rapide R. En effet, le lot témoin I a enregistré un GMH significativement élevé à celui du lot témoin L. L’indice de consommation du lot R et I est 50% plus bas que celui du poulet L. Concernant l’infection expérimentale par le virus H9N2, le groupe de poulet I et R ont présenté les signes cliniques et les lésions macroscopiques les plus sévères et accentués par rapport aux poulets du lot L à croissance lente. Mots clés : infection H9N2, croissance rapide, croissance intermédiaire, performance zootechniquePoultry meat is the most widely consumed animal protein due to its low price compared to other animal products. However, the poultry sector is constantly experiencing progress improving the productivity and organoleptic quality of poultry meat. To responds the challenges of food security and the requirements of citizens and consumers, the present work consists to study the zootechnical performances as well as the sensitivity to the H9N2 virus of cross-breed chicken with intermediate growth (I), compared to two breeds fast growing (R) and slow growing (L) chickens. The results of the study showed zootechnical performances of race I with intermediate growth similar to those of fast growing chicken R. Indeed, the control group I recorded a GMH significantly elevated to that of the control group L. The index consumption of lot R and I is 50% lower than that of chicken L. Concerning the experimental infection with the H9N2 virus, the group of chicken I and R presented the most severe and accentuated clinical signs and gross lesions compared to chickens of the slow breed L. Keywords: infection, H9N2, rapid growth, intermediate growth, slow growth, zootechnical performanc

Prévalence de la maladie de la bronchite infectieuse aviaire au Maroc entre Juin 2018 et Avril 2019

Avian infectious bronchitis (IB) is mainly an upper respiratory tract infection caused by infectious bronchitisvirus (IBV) belonging to the Coronaviridae family. This work aims to assess the prevalence of IBV in different regions of Morocco using real-time RT-PCR, in order to better understand the epidemiological situation of the disease in these regions. Epidemiological analyses have shown that the IBV circulates with a high prevalence of 61% between 2018 and 2019, thus, the results obtained were valued and evaluated by a statistical study using the SPSS version 13 (Statistical Package for the Social Sciences). IB circulated with distinct prevalence’s in the different regions of Morocco, but this difference was not statistically significant. A peak of positivity was found in the BeniMellal-Khenifra, Draa-Tafilalet, and Souss-Massa regions. On the other hand, a very high vaccination rate against IB (90% of farms) in Morocco has been observed. Keywords: Avian infectious bronchitis, real-time RT-PCR, Prevalence, MoroccoLa bronchite infectieuse aviaire (BI) est principalement une infection des voies respiratoires supérieures causée par le virus de la bronchite infectieuse aviaire (IBV) appartenant à la famille des Coronaviridae. Le présent travail a pour objectif d’évaluer la prévalence de l’IBVdans sept différentes régions du Maroc en utilisant la RT-PCR en temps réel, afin de mieux connaitre la situation épidémiologique de la maladie dans ces régions. L’analyse épidémiologique a montré que l’IBV a circulé avec une forte prévalence de 61% entre 2018 et 2019, ainsi, les résultats obtenues ont été valorisées et évaluées par une étude statistique via la version 13 du logiciel SPSS (Statistical Package for the Social Sciences). L’infection à l’IBV a circulé avec des prévalences distinctes dans les différentes régions du Maroc, mais cette différence n’était pas statistiquement significative. Un pic de positivité a été mis en évidence dans les régions BeniMellal-Khenifra, Draa-Tafilalet, et Souss-Massa. D’autre part, un taux de vaccination très élevé contre la BI (90% des élevages) au Maroc a été constaté. Mots clés: Bronchite infectieuse aviaire, RT-PCR en temps réel, Prévalence, Maro

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century