377 research outputs found
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Global Stability Analysis of Healthy Situation for a Coupled Model of Healthy and Cancerous Cells Dynamics in Acute Myeloid Leukemia
In this paper we aim to study the global stability of a coupled model of healthy and cancerous cells dynamics in healthy situation of Acute Myeloid Leukemia. We also clarify the effect of interconnection between healthy and cancerous cells dynamics on the global stability The interconnected model is obtained by transforming the PDE-based model into a nonlinear distributed delay system. Using Lyapunov approach, we derive necessary and sufficient conditions for global stability for a selected equilibrium point of particular interest (healthy situation). Simulations are conducted to illustrate the obtained results
Computational analysis of the behavior of atmospheric pollution due to demographic, structural factors, vehicular flow and commerce activities
According to the latest assessments made by the world health organization (WHO2016), the atmospheric pollution (air), has become one of the main causes of morbidity and mortality in the world, with a steep growth of respiratory diseases, increase in lung cancer, ocular complications, and dermis diseases [1,2,3]. Currently, there are governments which still underestimate investments in environmental care, turning their countries into only consumers and predators of the ecosystem [1,2,3]. Worldwide, several cities have been implementing different regional strategies to decrease environmental pollution, however, these actions have not been effective enough and significant indices of contamination and emergency declarations persist [1,2,3]. MedellÃn is one of the cities most affected by polluting gases in Latin America due to the high growth of construction sector, high vehicular flow, increase in commerce, besides a little assertive planting trees system, among other reasons [1,2,3]. With the purpose of providing new researching elements which benefit the improvement of air quality in the cities of the world, it is pretended to mathematically model and computationally implement the behavior of the flow of air, e.g., in zones in the city of MedellÃn to determine the extent of pollution by tightness, impact of current architectural designs, vehicular transport, high commerce flow, and confinement in the public transport system. The simulations allowed to identify spotlights of particulate tightness caused by architectural designs of the city which do not benefit air flow. Also, recirculating gases were observed in different zones of the city. This research can offer greater knowledge around the incidence of pollution generated by structures and architecture. Likewise, these studies can contribute to a better urban, structural and ecological reordering in cities, the implementation of an assertive arborization system, and the possibility to orientate effective strategies over cleaning (purification) and contaminant extracting systems
Intelligent IT Governance Platform: Strategic level
The objective of this work is the implementation of a new IT governance platform adaptable to any type of Information system architecture and any kind of business. The proposed platform is intelligent and independent to understand the business needs continuously changing, is distributed to involve all stakeholders and heterogeneous components, and scalable to accumulate the know-how of the company's IT Governance through a learning asset
Imagerie des fistules arterio-veineuses durales a drainage veineux peri -medullaire
Les fistules durales rachidiennes à drainage veineux périmédullaire constituent une pathologie d’individualisation récente. C’est les plus fréquentes des malformations vasculaires vertébromédullaires,elles se présentent sous la forme d’une myélopathie spastique progressive chez un sujet de plus de 40 ans. A partir d’une étude rétrospective des données cliniques et explorations radiologiques d’une série de 11 cas en IRM et artériographie médullaire, nous avons recensé l’ensemble des signes radiologiques qui orientent le diagnostic. L’IRM a montré un hypersignal T2 centromédullaire de façon constante ainsi que des vaisseaux périmédullaires pathologiques. L’angiographie médullaire reste l’examen clé pour le diagnostic. Elle a permit de montrer dans dix cas le shunt artério-veineux ainsi que ses afférences artériels et son retour veineux, permettant de planifier le traitement. Huit patients ont été pris en charge chirurgicalement avec exclusion de la fistule suivie d’une amélioration clinique. L’imagerie joue aussi un rôle important dans le suivi postthérapeutique. L’IRM permet de mettre en évidence la disparition progressive des anomalies initiales, signede l’efficacité du traitement. Les fistules artério-veineuses à drainage veineux périmédullaire sont une pathologie qui reste encore méconnue. La connaissance de tous ces éléments d’imagerie est fondamentalepour un diagnostic et une prise en charge précoces, seuls garants d’une bonne évolution après traitement
Reactivity of 3-hydroxy-3-methyl-2-butanone: Photolysis and \OH\ reaction kinetics
International audienceHydroxycarbonyl compounds are important secondary reaction products in the oxidation of Volatile Organic Compounds (VOCs) in the atmosphere. The atmospheric fate of these oxygenated \VOCs\ is however poorly understood, especially the relevance of the photolytic pathway. In this work, a combined investigation of the photolysis and temperature-dependent \OH\ radical reaction of 3-hydroxy-3-methyl-2-butanone (3H3M2B) is presented. A photolysis lifetime of about 4-5 days was estimated with a global quantum yield of 0.10. The \OH\ reaction rate coefficient follows the Arrhenius trend (298-356 K) and could be modelled through the following expression: k3H3M2B(T) = (5.12 ± 0.07) × 10−12 exp(−563 ± 119/T) in cm3 molecule−1 s−1. A 3H3M2B atmospheric lifetime of 15 days towards the \OH\ radical was evaluated. Our results showed that the photolysis pathway is the major degradation channel for 3H3M2B. Photolysis products were identified and quantified in the present work with a carbon balance of around 80% enabling a reaction mechanism to be proposed. The present work underlines the need for further studies on the atmospheric chemistry of oxygenated VOCs
Empirical Study on the Status of Moroccan Information Systems and Proposition of Approach for Choice of Best Practices for Good IT Governance
Today, the function of the chief information officer (CIO) has become part of the flow charts of many Moroccan companies [1]. Based on this statement, we did an empirical study in the first part of this work on the state of information systems (IS) Moroccan to know their strengths and weaknesses. The aim of the second part is to propose an approach based on the IT (information technology) frameworks helping CIOs to form their own repository of good practices to be applied in order to have good IT governance
An Empirical Study on the information systems in the Moroccan organizations: An explanatory model to decide differently and to optimize the IT governance
An information system, it's the key point of the success of companies [5] [6]. Where from the necessity of investing to develop information systems, these investments concern to infrastructures, application software's, set up systems, and existing processes.
Companies have to follow policies to manage well their investment of information systems in an economic and optimal way, it is the subject of this paper. To validate our subject, our hypothesis, a study of ground was necessary. We opted for an empirical study on the information systems of the high-level Moroccan organizations in various sectors, by basing itself on scientific foundations. The study and the data analysis allowed us to propose new simplified models
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