Identification of multitype branching processes

We solve the problem of constructing an asymptotic global confidence region for the means and the covariance matrices of the reproduction distributions involved in a supercritical multitype branching process. Our approach is based on a central limit theorem associated with a quadratic law of large numbers performed by the maximum likelihood or the multidimensional Lotka--Nagaev estimator of the reproduction law means. The extension of this approach to the least squares estimator of the mean matrix is also briefly discussed. On r\'{e}sout le probl\`{e}me de construction d'une r\'{e}gion de confiance asymptotique et globale pour les moyennes et les matrices de covariance des lois de reproduction d'un processus de branchement multitype et supercritique. Notre approche est bas\'{e}e sur un th\'{e}or\`{e}me de limite centrale associ\'{e} \`{a} une loi forte quadratique v\'{e}rifi\'{e}e par l'estimateur du maximum de vraisemblance ou l'estimateur multidimensionnel de Lotka--Nagaev des moyennes des lois de reproduction. L'extension de cette approche \`{a} l'estimateur des moindres carr\'{e}s de la matrice des moyennes est aussi bri\`{e}vement comment\'{e}e.Comment: Published at http://dx.doi.org/10.1214/009053605000000561 in the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

Volatile and Non-Volatile Single Electron Memory

Multi Tunnel Junctions (MTJs) have attracted much attention recently in the fields of Single-Electron Devices (SED) in particular Single-Electron Memory (SEM). In this paper, we have design and study a nano-device structure using a two dimensional array MTJs for Volatile and Non-Volatile-SEM, in order to analyze the impact of physical parameters on the performances. We investigate the single-electron circuit characteristics in our devices qualitatively, using single-electron Monte Carlo simulator SIMON. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3192

Low Voltage Totally Free Flexible RF MEMS Switch With Anti-Stiction System

This paper concerns a new design of RF MEMS switch combined with an innovative process which enable low actuation voltage (<5V) and avoid stiction. First, the structure described with principal design issues, the corresponding anti-stiction system is presented and FEM simulations are done. Then, a short description of the process flow based on two non polymer sacrificial layers. Finally, RF measurements are presented and preliminary experimental protocol and results of anti-stiction validation is detailed. Resulting RF performances are -30dB of isolation and -0.45dB of insertion loss at 10 GHz.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838

Improving supply chain practices in a luxury fashion company in the Middle East and the Near East

Supply chain practices have a high impact on a company’s ability to compete in the market as well as in its profitability. The positioning of its inventory and its supply chain practices determine the ability to react to changes in demand, as well as the ability to fulfil customer’s requests. Cultural characteristics as well as long term practices can influence both its efficiency and effectiveness. The purpose of this paper is to analyse supply chain practices and its impact in supply chain performance in the luxury fashion industry, which represents a market not widely studied in the supply chain management literature. Particularly, this paper aims at exploring a supply chain of luxury fashion products operating in the Middle East and the Near East while assessing the efficiency and effectiveness gains from supply chain adjustments. Data was collected using direct observation and semi-structured interviews at the office of the company for the Middle East and the Near East. Findings show that the main constraint to improve customer service is lack of visibility and long lead times, which lead retailers to frequent shortage gaming practices. Analysis and managerial recommendations lead to position decoupling points, reduce lead times and simultaneously reduce customer complaints and the bullwhip effect while improving visibility and forecasting practices.info:eu-repo/semantics/publishedVersio

Panton-Valentine leukocidin positive sequence type 80 methicillin-resistant Staphylococcus aureus carrying a staphylococcal cassette chromosome mec type IVc is dominant in neonates and children in an Algiers hospital

Methicillin-resistant Staphylococcus aureus (MRSA) is a major antimicrobial drug-resistant pathogen causing serious infections. It was first detected in healthcare settings, but in recent years it has also become disseminated in the community. Children and young adults are most susceptible to infection by community-acquired (CA) MRSA strains. In this study 25 MRSA isolates implicated in infections of neonates and children admitted to an Algiers hospital during an 18 month period were characterized by molecular methods including staphylococcal cassette chromosome (SCC) mec typing, PCR amplification of pvl genes, pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Fifteen out of 25 isolates were from hospital-acquired infections. Twenty-four isolates carried SCCmec type IVc and belonged to the sequence type (ST) 80, one isolate carried SCCmec type II and was ST 39. Twenty-two out of 24 ST80-MRSA-IVc isolates carried pvl genes. Our results suggest that the Panton-Valentine leukocidin positive ST80- MRSA-IVc is the dominant MRSA clone causing disease in neonates and children in Algiers

A modular IoT platform for real-time indoor air quality monitoring

The impact of air quality on health and on life comfort is well established. In many societies, vulnerable elderly and young populations spend most of their time indoors. Therefore, indoor air quality monitoring (IAQM) is of great importance to human health. Engineers and researchers are increasingly focusing their efforts on the design of real-time IAQM systems using wireless sensor networks. This paper presents an end-to-end IAQM system enabling measurement of CO2, CO, SO2, NO2, O3, Cl2, ambient temperature, and relative humidity. In IAQM systems, remote users usually use a local gateway to connect wireless sensor nodes in a given monitoring site to the external world for ubiquitous access of data. In this work, the role of the gateway in processing collected air quality data and its reliable dissemination to end-users through a web-server is emphasized. A mechanism for the backup and the restoration of the collected data in the case of Internet outage is presented. The system is adapted to an open-source Internet-of-Things (IoT) web-server platform, called Emoncms, for live monitoring and long-term storage of the collected IAQM data. A modular IAQM architecture is adopted, which results in a smart scalable system that allows seamless integration of various sensing technologies, wireless sensor networks (WSNs) and smart mobile standards. The paper gives full hardware and software details of the proposed solution. Sample IAQM results collected in various locations are also presented to demonstrate the abilities of the system. 2018 by the authors. Licensee MDPI, Basel, Switzerland.Acknowledgments: This publication was made possible by the National Priority Research Program (NPRP) award (NPRP6-600-2-250) from the Qatar National Research Fund (QNRF), a member of the Qatar Foundation. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of QNRF.Scopu

New fast arctangent approximation algorithm for generic real-time embedded applications

Fast and accurate arctangent approximations are used in several contemporary applications, including embedded systems, signal processing, radar, and power systems. Three main approximation techniques are well-established in the literature, varying in their accuracy and resource utilization levels. Those are the iterative coordinate rotational digital computer (CORDIC), the lookup tables (LUTs)-based, and the rational formulae techniques. This paper presents a novel technique that combines the advantages of both rational formulae and LUT approximation methods. The new algorithm exploits the pseudo-linear region around the tangent function zero point to estimate a reduced input arctangent through a modified rational approximation before referring this estimate to its original value using miniature LUTs. A new 2nd order rational approximation formula is introduced for the first time in this work and benchmarked against existing alternatives as it improves the new algorithm performance. The eZDSP-F28335 platform has been used for practical implementation and results validation of the proposed technique. The contributions of this work are summarized as follows: (1) introducing a new approximation algorithm with high precision and application-based flexibility; (2) introducing a new rational approximation formula that outperforms literature alternatives with the algorithm at higher accuracy requirement; and (3) presenting a practical evaluation index for rational approximations in the literature. - 2019 by the authors. Licensee MDPI, Basel, Switzerland.Funding: The publication of this article was funded by the Qatar National Library.Scopu

Staphylococcal cassette chromosome mec typing and meca sequencing in methicillin-resistant staphylococci from Algeria: A highly diversified element with new mutations in mecA

Genetic mechanisms of methicillin resistance are still relevant in staphylococci. The aims of this study are to assess the possible exchanges of staphylococcal cassette chromosome mec (SCCmec) among isolates of methicillin-resistant staphylococci (MRS) and to check for known or new mutations in mecA DNA. A total of 35 MRS non-repetitive isolates were recovered, including 20 Staphylococcus haemolyticus, 7 Staphylococcus aureus, 4 Staphylococcus sciuri, 2 Staphylococcus saprophyticus and 1 isolate each of Staphylococcus xylosus and Staphylococcus lentus. Only 16 of the 35 strains were assigned to known SCCmec types: 7 SCCmec VII, 6 SCCmec IV and 3 SCCmec III, with possible horizontal transfer of the SCCmec VII from methicillin-resistant S. haemolyticus to methicillin-susceptible S. aureus. mecA gene sequencing in ten selected isolates allowed description of nine punctual mutations, seven of which were reported for the first time. The most frequent mutation was G246E, identified in isolates of methicillin-resistant S. aureus, S. sciuri, S. saprophyticus and S. lentus. These results emphasized the high degree of genetic diversity of SCCmec element in MRS and describe new missense mutations in mecA, which might be important in understanding the evolution of methicillin and new b-lactam resistance

Chronic dehydration affects hydroelectrolytic equilibrium and adrenal gland morphology in wistar rat: comparison with Gerbillus tarabuli

Shortage of water supply is the most stressful condition that can meet man and animals. Since the adrenal gland plays a pivotal role in the stress response, the objective of this work is to study, in the male Wistar rat, the repercussions of chronic dehydration on adrenal gland structure compared to that of a desert rodent: Gerbillus tarabuli. Adults and male Wistar rats and gerbils were divided into: i) control rats (n=8) given free access to tap water); ii) dehydrated rats (n=8) given 2% NaCl solution ad libitum for 7 days and (iii) G.tarabuli (n=6) given barely seeds ad libitum without access to water. Chronic dehydration caused strong adreno-chromaffin cells degranulation in rats. For the gerbils, adrenal zona fasciculate and medulla features suggest respectively an increased production and release of glucocorticoides but a basal stress hormones release. These results suppose that shortage of water in arid environment does not represent a stress factor for this species.Keywords: adrenal gland; chronic dehydration; plasmatic parameters; histology; Wistar rat; Gerbillus tarabul

Hypocalcémie post-thyroïdectomie

Introduction : L’hypocalcémie est la complication la plus préoccupante de la thyroïdectomie totale. Elle impose un traitement substitutif et un suivi à vie. Objectifs : Le but de cette étude est d’évaluer l’incidence de l’hypocalcémie après chirurgie et d’étudier sa corrélation avec les caractéristiques cliniques, biologiques et le type de chirurgie pratiqué. Matériels et méthodes : Etude rétrospective portant sur 488 cas de thyroïdectomies, opérées entre 1992 et 1996. L’hypocalcémie est définie par une calcémie inférieure à 80 mg/l «2 mmol/l ». Les patients, toujours dépendants d’un traitement substitutif un an après la chirurgie, ont été considérés comme ayant une hypocalcémie définitive. Résultats : Dans notre étude, 368 patients ont eu une thyroïdectomie totale et 120 ont eu une thyroïdectomie subtotale. Le goitre multinodulaire était la pathologie la plus fréquente, noté dans 359 cas, suivie des cancers thyroïdiens noté dans 83 cas. L’hypocalcémie postopératoire a été retrouvée chez 54 patients (11,06%) dont 25 étaient asymptomatique. Cette hypocalcémie s’est révélée définitive chez 14 d’entre eux (2,8%). Nous n’avons pas trouvé de corrélation statistiquement significative entre l’hypoparathyroïdie définitive et les caractéristiques cliniques biologiques et le type de chirurgie.Conclusion : Dans la plupart des cas, l’hypocalcémie est liée à un hypoparathyroïdisme transitoire, secondaire au traumatisme ou à la dévascularisation des parathyroïdes. L’hypoparathyroïdie définitive est rare, elle est toujours secondaire à une lésion irréversible des parathyroïdes. Les caractéristiques cliniques initiales des patients et les examens biologiques précoces ne permettent pas de prédire l’évolution.Mots-clés : Thyroïde, chirurgie, hypocalcémie, parathyroïde