Expression analytique de l’EVM pour les signaux multiporteuses : Impact conjoint des non-linéarités de l’amplificateur de puissance et de la fonction de prédistorsion

National audience"Dans cet article, nous proposons une étude analytique de l’impact des non-linéarités des amplificateurs de puissance sur des signauxissus de processus de modulation OFDM (Orthogonal Frequency Division Multiplexing). Notre analyse porte sur une structure d’émetteur équipéd’une fonction de prédistorsion placée avant l’amplificateur. Les expressions analytiques de l’EVM (Error Vector Magnitude) du signal amplifiésont calculées avec ou sans prédistorsion. Nous fournissons alors les expressions analytiques de l’EVM sous la forme d’un développement ensérie de fonctions Gamma, qui dépend directement du facteur de transition de l’amplificateur et du facteur de prédistorsion. Les résultats dessimulations confirment la précision de nos expressions analytiques, même en limitant la série à un ordre 4.

What If I Do Not Match? Scrambling for a Spot and Going Outside the Match.

Matching into emergency medicine (EM) is getting progressively more competitive. Applicants must therefore prepare for the possibility of not matching and, accordingly, be ready to participate in the Supplemental Offer and Acceptance Program (SOAP). In this article, we elaborate on the SOAP and the options for applicants who fail to match during Match Week. Alternative courses of action include applying for a preliminary year, matching into a categorical residency program, or aiming to secure EM spots outside the Match through the Council of Emergency Medicine Residency Directors, Society for Academic Emergency Medicine, and American Association of Medical Colleges

Are You Applying to More Than One Specialty?

Although the majority of U.S. medical students predominantly apply to only one specialty, some apply to more than one. When it comes to emergency medicine (EM), applicants may apply to additional specialties due to several reasons: being international medical graduates as well as their inability to make a decision regarding the choice of specialty, fear from the growing competitiveness of EM, or the desire to stay in a specific geographic area. Accordingly, in this article we aim to guide medical students through the process of applying to more than one specialty, including using the Electronic Residency Application Service application, writing a personal statement, getting letters of recommendation, and an Early Match. Moreover, we elaborate on the effect of applying to more than one specialty on a student's application to a residency in EM

What Do Program Directors Look for in an Applicant?

Program directors (PDs) are faced with an increasing number of applicants to emergency medicine (EM) and a limited number of positions. This article will provide candidates with insight to what PDs look for in an applicant. We will elaborate on the performance in the emergency medicine clerkship, interview, clinical rotations (apart from EM), board scores, Alpha Omega Alpha membership, letters of recommendation, Medical Student Performance Evaluation or dean’s letter, extracurricular activities, Gold Humanism Society membership, medical school attended, research and scholarly projects, personal statement, and commitment to EM. We stress the National Resident Matching Program process and how, ultimately, selection of a residency is equally dependent on an applicant’s selection process

EMT Markers in Locally-Advanced Prostate Cancer: Predicting Recurrence?

Background: Prostate cancer (PCa) is the second most frequent cause of cancer-related death in men worldwide. It is a heterogeneous disease at molecular and clinical levels which makes its prognosis and treatment outcome hard to predict. The epithelial-to-mesenchymal transition (EMT) marks a key step in the invasion and malignant progression of PCa. We sought to assess the co-expression of epithelial cytokeratin 8 (CK8) and mesenchymal vimentin (Vim) in locally-advanced PCa as indicators of EMT and consequently predictors of the progression status of the disease.Methods: Co-expression of CK8 and Vim was evaluated by immunofluorescence (IF) on paraffin-embedded tissue sections of 122 patients with PCa who underwent radical prostatectomies between 1998 and 2016 at the American University of Beirut Medical Center (AUBMC). EMT score was calculated accordingly and then correlated with the patients' clinicopathological parameters and PSA failure.Results: The co-expression of CK8/Vim (EMT score), was associated with increasing Gleason group. A highly significant linear association was detected wherein higher Gleason group was associated with higher mean EMT score. In addition, the median estimated biochemical recurrence-free survival for patients with < 25% EMT score was almost double that of patients with more than 25%. The validity of this score for prediction of prognosis was further demonstrated using cox regression model. Our data also confirmed that the EMT score can predict PSA failure irrespective of Gleason group, pathological stage, or surgical margins.Conclusion: This study suggests that assessment of molecular markers of EMT, particularly CK8 and Vim, in radical prostatectomy specimens, in addition to conventional clinicopathological prognostic parameters, can aid in the development of a novel system for predicting the prognosis of locally-advanced PCa

Analyse théorique des distorsions dans la bande et en dehors de la bande de transmission pour les signaux à porteuses multiples : Impact conjoint des non-linéarités de l'amplificateur de puissance et effets de mémoire et prédistorsion

OFDM multicarrier techniques are now widely deployed in most wireless communication systems, in particular in cellularnetworks (L TE), broadcast networks (DVB) and WiFi networks. However, multi-carrier modulations are characterized by avery large dynamic amplitude measured by the Peak to Average Power Ratio (PAPR). which prevents radio frequencydesigners to feed the signal at the optimal point of the Power Amplifier (PA) which reduces the PA energy efficiency. Inliterature, the PAPR reduction and linearization techniques are the main approaches to solve the PAPR problem, the PAnonlinearities problem. as well as the low PA efficiency problem.The approach developed in this thesis was to study an intelligent solution for future implementations to control thereduction of PAPR and the linearization steps in a flexible way according to some predefined parameters so that theybecome adaptive and self-configurable. More specifically, our work focused on the analytical analysis of in-band measureby the Error Vector Magnitude (EVM) and out-of-band distortions measured by the Adjacent Chanel Power Ratio (ACPR)for clipped multicarrier signals taking into account the impact of non-linear amplification, memory effects and predistortion.In particular. many analytical results complemented by simulation results to evaluate the EVM and ACPR are proposed.These analytical expressions depend on the PA characteristics taking into account or not the PA memory effects and theuse of clipping and pre-distortion techniques. lt is worthwhile to note that our proposed theoretical analyses could be veryuseful for optimizing future transmitter efficiency and linearity in the field of broadcasting applications for the deployment oDVB-T2 transmitters as well as for L TE cellular networks.Les techniques multiporteuses de type OFDM sont aujourd'hui largement déployées dans tous les systèmes de communication sans fils notamment dans les réseaux cellulaires (L TE), les réseaux de diffusion (DVB) ou encore les réseaux WiFi. Cependant, les modulations multiporteuses se caractérisent par une très grande dynamique mesurée par le Peak to Average Power Ratio (PAPR), ce qui empêche d'alimenter l'amplificateur de puissance non linéaire (utilisé avant l'émission des signaux) à son point optimal et ainsi conduit à diminuer son efficacité énergétique. Des techniques de réduction du PAPR peuvent alors être mises en oeuvre pour réduire le PAPR du signal et des techniques de prédistorsion peuvent alors être utilisées pour compenser les non-linéarités de l'amplificateur de puissance. L'approche développée dans le cadre de cette thèse a pour objectif d'étudier une solution intelligente pour les implémentations futures pour contrôler la réduction du PAPR et les étapes de linéa risation de manière flexible en fonction de certains paramètres prédéfinis afin qu'ils deviennent adaptatifs et auto-configurables. Plus précisément, notre travail a principalement porté sur l'analyse des différentes distorsions dans la bande (in-band distortions)mesurées par I'EVM ou Error Vector Magnitude et en dehors de la bande de transmission (out-of-band distortions) mesurées par I'ACPR ou Adjacent Channel Power Ratio de signaux à porteuses multiples. En particulier de nombreux résultats analytiques complétés par des résultats de simulation permettant d'évaluer I'EVM et I'ACPR en fonction des caractéristiques de l'amplification nonlinéaire en prenant en compte ou pas l'effet mémoire de l'amplificateur et la mise en oeuvre de techniques d'écrêtage et de pré-distorsion ont été obtenus. Ces résultats constituent une étape importante dans l'optimisation globale de la complexité, de la linéarité et de l'efficacité énergétique des émetteurs aussi bien pour la diffusion de la télévision numérique que pour les réseaux cellulaires de 4 ème génération (L TE) ou de 5""' génération

Performance Analysis of a Multiplex With Different PAPR Reduction Techniques

International audienc

Outpatient Management of Cancer Patients During the COVID-19 Pandemic

Coronavirus disease 2019 (COVID-19) was first identified in Wuhan, China. In no time, SARS-CoV- 2 found its way to the whole world, to be declared as a pandemic by the World Health Organization (WHO) on March 11th, 2020. As this disease continues to take its toll on the world as a whole, we, at the American University of Beirut Medical Center (AUBMC), believe that it is essential to protect those who are at a particularly high-risk for contracting the virus, namely cancer patients. Besides complying with all the protective measures recommended by WHO, we developed quality improvement plans for the outpatient management of febrile neutropenia, pneumonia and pulmonary embolism in cancer patients. The aim of such plans is to offer adequate management for cancer patients on an outpatient basis, whenever possible, and thus limit their admission rates together with their risk of contracting the novel virus, SARS-CoV- 2