Global Throughput Maximization of a Hybrid Unicast-Broadcast Network for Linear Services

International audienceAn exponential growth of the mobile data traffic is expected in future networks. The reason of this growth is related to the increasing popularity of linear services such as mobile TV, live and sports events, which may lead to the delivery of the same contents to a large audience. Recent studies have shown that network cooperation is a promising candidate to deal with such an issue. This paper investigates, from a planning perspective, the optimization of a hybrid unicast/broadcast network for linear services. We introduce an analytical approach with the aim of stating an optimization problem on the hybrid network configuration, namely in terms of the sharing between the unicast and broadcast modes to deliver a particular service. We show by simulation the existence of an optimal operation point which leads to the maximization of the overall throughput of the hybrid network under the constraint of a minimum service success rate

Electromagnetic-field distribution measurements in the soft s-ray range: full characterization of a soft x-ray laser beam

Includes bibliographical references (pages 183901-4).We report direct measurement of the electromagnetic-field spatial distribution in a neonlike Ar capillary discharge-driven soft x-ray laser beam. The wave front was fully characterized in a single shot using a Shack-Hartmann diffractive optics sensor. The wave front was observed to be dependent on the discharge pressure and capillary length, as a result of beam refraction variations in the capillary plasma. The results predict ~70% of the laser beam energy can be focused into an area 4 times the size of the diffraction-limited spot, reaching intensities of ~4 × 1013 W/cm2

Evaluation d'un système d'assistance à la conduite de fauteuil roulant électrique

National audienceL'utilisation d'un fauteuil roulant électrique est pour nombre de personnes en situation de handicap le seul mode de déplacement autonome leur donnant la possibilité d'une liberté de déplacement en extérieur ou en intérieur. La maîtrise de ce type d'aide technique peut être rendue difficile du fait de handicaps sensoriels, notamment visuels, ou de troubles de commande du membre supérieur. L'objectif de cette étude est d'évaluer un système électronique embarquée d'assistance à la conduite mis au point par l'INSA. Ce système permet de détecter les obstacles puis de corriger vitesse et trajectoire pour éviter les collisions et améliorer la qualité de la trajectoire

IgM memory B cells: a mouse/human paradox

Humoral memory is maintained by two types of persistent cells, memory B cells and plasma cells, which have different phenotypes and functions. Long-lived plasma cells can survive for a lifespan within a complex niche in the bone marrow and provide continuous protective serum antibody levels. Memory B cells reside in secondary lymphoid organs, where they can be rapidly mobilized upon a new antigenic encounter. Surface IgG has long been taken as a surrogate marker for memory in the mouse. Recently, however, we have brought evidence for a long-lived IgM memory B cell population in the mouse, while we have also argued that, in humans, these same cells are not classical memory B cells but marginal zone (MZ) B cells which, as opposed to their mouse MZ counterpart, recirculate and carry a mutated B cell receptor. In this review, we will discuss these apparently paradoxical results

Strategy for the management of diabetic macular edema: the European Vitreo-Retinal Society macular edema study

Objective. To compare the efficacy of different therapies in the treatment of diabetic macular edema (DME). Design. Nonrandomized, multicenter clinical study. Participants. 86 retina specialists from 29 countries provided clinical information on 2,603 patients with macular edema including 870 patients with DME. Methods. Reported data included the type and number of treatment(s) performed, the pre-and posttreatment visual acuities, and other clinical findings.The results were analyzed by the French INSEE (National Institute of Statistics and Economic Studies). Main Outcome Measures. Mean change of visual acuity and mean number of treatments performed. Results.The change in visual acuity over time in response to each treatment was plotted in second order polynomial regression trend lines. Intravitreal triamcinolone monotherapy resulted in some improvement in vision. Treatmentwith threshold or subthreshold grid laser also resulted in minimal vision gain. Anti-VEGF therapy resulted in more significant visual improvement. Treatment with pars plana vitrectomy and internal limiting membrane (ILM) peeling alone resulted in an improvement in vision greater than that observed with anti-VEGF injection alone. In our DME study, treatment with vitrectomy and ILM peeling alone resulted in the better visual improvement compared to other therapies

Year in review in Intensive Care Medicine, 2008: II. Experimental, acute respiratory failure and ARDS, mechanical ventilation and endotracheal intubation

SCOPUS: re.jinfo:eu-repo/semantics/publishe

Vaccine breakthrough hypoxemic COVID-19 pneumonia in patients with auto-Abs neutralizing type I IFNs

Life-threatening `breakthrough' cases of critical COVID-19 are attributed to poor or waning antibody response to the SARS- CoV-2 vaccine in individuals already at risk. Pre-existing autoantibodies (auto-Abs) neutralizing type I IFNs underlie at least 15% of critical COVID-19 pneumonia cases in unvaccinated individuals; however, their contribution to hypoxemic breakthrough cases in vaccinated people remains unknown. Here, we studied a cohort of 48 individuals ( age 20-86 years) who received 2 doses of an mRNA vaccine and developed a breakthrough infection with hypoxemic COVID-19 pneumonia 2 weeks to 4 months later. Antibody levels to the vaccine, neutralization of the virus, and auto- Abs to type I IFNs were measured in the plasma. Forty-two individuals had no known deficiency of B cell immunity and a normal antibody response to the vaccine. Among them, ten (24%) had auto-Abs neutralizing type I IFNs (aged 43-86 years). Eight of these ten patients had auto-Abs neutralizing both IFN-a2 and IFN-., while two neutralized IFN-omega only. No patient neutralized IFN-ss. Seven neutralized 10 ng/mL of type I IFNs, and three 100 pg/mL only. Seven patients neutralized SARS-CoV-2 D614G and the Delta variant (B.1.617.2) efficiently, while one patient neutralized Delta slightly less efficiently. Two of the three patients neutralizing only 100 pg/mL of type I IFNs neutralized both D61G and Delta less efficiently. Despite two mRNA vaccine inoculations and the presence of circulating antibodies capable of neutralizing SARS-CoV-2, auto-Abs neutralizing type I IFNs may underlie a significant proportion of hypoxemic COVID-19 pneumonia cases, highlighting the importance of this particularly vulnerable population

Discutindo a educação ambiental no cotidiano escolar: desenvolvimento de projetos na escola formação inicial e continuada de professores

A presente pesquisa buscou discutir como a Educação Ambiental (EA) vem sendo trabalhada, no Ensino Fundamental e como os docentes desta escola compreendem e vem inserindo a EA no cotidiano escolar., em uma escola estadual do município de Tangará da Serra/MT, Brasil. Para tanto, realizou-se entrevistas com os professores que fazem parte de um projeto interdisciplinar de EA na escola pesquisada. Verificou-se que o projeto da escola não vem conseguindo alcançar os objetivos propostos por: desconhecimento do mesmo, pelos professores; formação deficiente dos professores, não entendimento da EA como processo de ensino-aprendizagem, falta de recursos didáticos, planejamento inadequado das atividades. A partir dessa constatação, procurou-se debater a impossibilidade de tratar do tema fora do trabalho interdisciplinar, bem como, e principalmente, a importância de um estudo mais aprofundado de EA, vinculando teoria e prática, tanto na formação docente, como em projetos escolares, a fim de fugir do tradicional vínculo “EA e ecologia, lixo e horta”.Facultad de Humanidades y Ciencias de la Educació

Motivation entrepreneuriale et logique d’action du créateur

L’objet de cette recherche est de faire émerger les ressorts de la motivation entrepreneuriale et de repérer les logiques d’action des créateurs d’entreprise (projets) associées à chaque dimension de cette attitude. Plus précisément, l’étude vise à répondre aux deux questions suivantes : Quels sont les besoins et leur intensité à l’origine de la création d’entreprise ? Et dans quelle mesure la motivation entrepreneuriale influence-t-elle les projets des entrepreneurs ?À partir des questionnaires à l’attention de chefs d’entreprises nouvellement installés, nous recherchons les ressorts de la motivation entrepreneuriale (besoins et intensité de ces derniers), ses antécédents et les logiquesd’action du créateur (imitation, innovation-aventure, reproduction et innovation-valorisation). Cette étude s’appuie sur un cadre théorique issu de recherches sur la motivation et l’entrepreneuriat. Une série de relations de causalité est retenue puis testée. L’analyse permet de tirer un ensemble de conclusions sur la motivation entrepreneuriale.Les chemins de la motivation nous conduisent à des logiques d’action liées à des projets innovants et éclairent le phénomène de reproduction (ou mimétisme) que l’on observe parfois chez les créateurs d’entreprise. À l’origine, on relève des objectifs de développement et d’indépendance. Dans le premier cas, le créateur espère que son entreprise lui apportera des résultats tangibles sur les plans financier et matériel. Dans le second cas, l’entrepreneur est conscient que son projet lui demandera de s’investir de façon autonome sur l’ensemble des dimensions de son entreprise (gestion, commercialisation, etc.). Sur le chemin de la logique d’action de valorisation, on retrouve la non-aversion pour le risque, l’exploitation d’un contexte porteur conjuguée à une maîtrise des compétences et à un besoin de créativité. Ces deux dimensions sont associées à un objectif d’indépendance. La logique de reproduction est motivée par un sentiment de confiance en soi (locus of control, LOC) et répond à un objectif de développement de l’entreprise.The aim of this research was to analyse the impetus of entrepreneurial motivation, to identify the reasons for action taken by entrepreneurs and to assess any contextual factors. More specifically, the study answered the following question : do links exist between entrepreneurial motivation, the reasons for action taken by entrepreneurs and their perceptions in relation to their project goals ?Based on questionnaires completed by newly established business leaders, we evaluated the impetus of entrepreneurial motivation (including their needs and strengths), identified the reasons for action taken by entrepreneurs and assessed the contextual factors. This study builds on a theoretical framework derived from research into motivation and entrepreneurship. We particularly drew our inspiration from recent models that attempt to understand entrepreneurial motivation which we supplemented with a typology of reasons for action taken by entrepreneurs. A series of causal relationships were identified and tested. The analysis allowed us to draw conclusions with regard to entrepreneurial motivation.Research into motivation highlighted the reasons for action taken in relation to innovative projects. Initially, we identified development and commitment objectives among these reasons. In one case, the entrepreneur hoped his company would bring him tangible financial and material results. In another, the entrepreneur was aware that his project would require him to invest in routine management activities and difficult business practices. Research into the reasons for improvement action taken highlighted the requirements for risk management and control. The exploitation of an enabling environment satisfied the entrepreneur’s requirement for control and was associated with a risk adverse entrepreneur. Projects described as adventurous, with the starting objective of tangible rewards, were likely to meet recognition requirements.La finalidad de esta investigación es que emerjan los mecanismos de la motivación empresarial, descubrir la lógica de acción de los emprendedores y evaluar los elementos contextuales. En particular, el estudio nos llevará a responder a la siguiente pregunta : ¿Existe un vínculo entre la motivación empresarial, la lógica de actuación de los emprendedores y algunas de sus percepciones en cuanto a los objetivos de su proyecto ?A partir de los cuestionarios dirigidos a los gerentes de las empresas de reciente implantación, evaluaremos los mecanismos de la motivación empresarial (necesidades e intensidades), observaremos la lógica de actuación del emprendedor y consideraremos los elementos contextuales. Este estudio se apoya dentro de un marco teórico derivado de investigaciones sobre la motivación y el espíritu emprendedor. Nos hemos inspirado concretamente en modelos recientes que intentan aprehender la motivación empresarial y que nosotros hemos completado con ayuda de una tipología de las lógicas de actuación de los emprendedores. Se han recogido y evaluado una serie de relaciones de causalidad. Este análisis permitirá obtener una serie de conclusiones sobre la motivación empresarial.Los caminos de la motivación nos conducirán hacia unas lógicas de actuación relacionadas con proyectos innovadores. Se identificarán en origen los objetivos de desarrollo y compromiso. En el primer caso, el emprendedor espera que su empresa le aporte resultados tangibles, es decir en términos financieros y materiales. En el segundo caso, el empresario es consciente de que su proyecto requerirá invertir en una gestión, a veces rutinaria, y en propuestas comerciales, a menudo difíciles. En el camino de la lógica de actuación de valorización, encontraremos las necesidades de control y de riesgo. La explotación de un contexto de apoyo permitirá satisfacer la necesidad de control presente en el emprendedor y que se asocia a un empresario que no busca riesgos. Los proyectos calificados como arriesgados, y como punto de partida el de obtener recompensas tangibles, son susceptibles de satisfacer las necesidades de reconocimiento.Ziel der vorliegenden Forschungsarbeit ist es, die Quellen unternehmerischer Motivation sowie die Handlungslogiken von Unternehmensgründern (Projektleadern) ausfindig zu machen und somit folgende Fragen zu beantworten : Welche Bedürfnisse in welcher Intensität stehen am Anfang einer Unternehmensgründung und inwiefern beeinflusst die unternehmerische Motivation die unternehmerischen Projekte ?Mithilfe einer Umfrage bei Geschäftsführern von kürzlich gegründeten Unternehmen untersuchen wir die Quellen unternehmerischer Motivation (Bedürfnisse und Intensität dieser), die Vorbedingungen sowie die Handlungslogiken der Gründer (Imitation, Innovationsabenteuer, Reproduktion und Innovationsvalorisation). Theoretisch ist die Studie auf den Motivationstheorien und den Ansätzen zum Unternehmertum aufgebaut. Eine Serie von kausalen Wirkungsbeziehungen wurde statistisch getestet. Die Erkenntnisse daraus lassen Schlüsse zur unternehmerischen Motivation zu.Die Ansätze zur Motivationen dienen zur Erklärung von Handlungslogiken im Zusammenhang mit innovativen Projekten und dem Phänomen der Imitation bei Unternehmensgründern. Es werden zwei grundsätzliche Ziele unterschieden : Entwicklung und Unabhängigkeit. Im ersten Fall erwartet der Unternehmer, dass das Projekt ihm finanzielle und materielle Erträge einbringt. Der Unternehmer mit dem Unabhängigkeitsmotiv ist sich bewusst, dass er sich ganzheitlich in sein Projekt einbringen muss. Bei den unterschiedlichen Handlungslogiken finden sich die fehlende Risikoaversion, Kombination von einem günstigen Umfeld mit bestehenden Fähigkeiten sowie ein Bedürfnis nach kreativer Tätigkeit. Diese Dimensionen sind mit dem Motiv der Unabhängigkeit verbunden. Die Logik der Reproduktion ist durch die Kontrollüberzeugung motiviert und adressiert das Bedürfnis der Entwicklung des Unternehmens