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Search Results: 1 - 10 of 14468 matches for " El Ahmadi Cheikh "
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Efficiency Evaluation Metrics for Wireless Intelligent Sensors Applications
Saad Chakkor,El Ahmadi Cheikh,Mostafa Baghouri,Abderrahmane Hajraoui
Computer Science , 2014, DOI: 10.5815/ijisa.2014.10.01
Abstract: The metrology field has been progressed with the appearance of the wireless intelligent sensor systems providing more capabilities such as signal processing, remote multi-sensing fusion etc. This kind of devices is rapidly making their way into medical and industrial monitoring, collision avoidance, traffic control, automotive and others applications. However, numerous design challenges for wireless intelligent sensors systems are imposed to overcome the physical limitations in data traffic, such as system noise, real time communication, signal attenuation, response dynamics, power consumption, and effective conversion rates etc, especially for applications requiring specific performances. This paper analyzes the performance metrics of the mentioned sensing devices systems which stands for superior measurement, more accuracy and reliability. Study findings prescribe researchers, developers/ engineers and users to realizing an optimal sensing motes design strategy that offers operational advantages which can offer cost-effective solutions for an application.
Comparative Performance Analysis of Wireless Communication Protocols for Intelligent Sensors and Their Applications
Saad Chakkor,El Ahmadi Cheikh,Mostafa Baghouri,Abderrahmane Hajraoui
Computer Science , 2014, DOI: 10.14569/IJACSA.2014.050413
Abstract: The systems based on intelligent sensors are currently expanding, due to theirs functions and theirs performances of intelligence: transmitting and receiving data in real-time, computation and processing algorithms, metrology remote, diagnostics, automation and storage measurements...The radio frequency wireless communication with its multitude offers a better solution for data traffic in this kind of systems. The mains objectives of this paper is to present a solution of the problem related to the selection criteria of a better wireless communication technology face up to the constraints imposed by the intended application and the evaluation of its key features. The comparison between the different wireless technologies (Wi-Fi, Wi-Max, UWB, Bluetooth, ZigBee, ZigBeeIP, GSM/GPRS) focuses on their performance which depends on the areas of utilization. Furthermore, it shows the limits of their characteristics. Study findings can be used by the developers/ engineers to deduce the optimal mode to integrate and to operate a system that guarantees quality of communication, minimizing energy consumption, reducing the implementation cost and avoiding time constraints.
The Gendering of Death in Kitāb al-‘Iqd al-Farīd
El Cheikh, Nadia Maria
Al-Qantara : Revista de Estudios Arabes , 2010,
Abstract: This article studies a subsection of the adab compilation of Ibn ‘Abd Rabbih’s, al-‘Iqd al-farīd, namely “The Book of Lamentations, Condolences, and Elegies”. The article analyzes al-‘Iqd’s ideological function, specifically, the way gender is organized through the occasion of death. It locates what seems to be repressed in the text attempting to determine what material was ignored, buried, end edited, and how priorities were arranged. It is the contention of this article that al-‘Iqd, as an exemplary text, not only reflects a dominant ideology, but contributes towards the dominant discourse by shaping mental and social life. Este artículo estudia la sección de la recopilación de adab del ‘Iqd al-farīd de Ibn ‘Abd Rabbih llamada “El Libro de Lamentaciones, Condolencias y Elegías”. Se analiza la función ideológica del ‘Iqd, concretamente la manera en que se organiza el género con ocasión de la muerte. Localiza lo que parece haberse reprimido en el texto en un intento por determinar el material que fue pasado por alto, enterrado o alterado, y estudia la organización de sus prioridades. El artículo sostiene que el ‘Iqd, en su función de texto ejemplar, no se limita a reflejar una ideología dominante sino que hace una contribución al discurso dominante por su manera de dar forma a la vida intelectual y social.
Myorelaxant and Spasmolytic Effects of Globularia alypum L. Extract on Rabbit Jejunum
A. Chokri,R. Doukali,K. El Abida,R. Ben Cheikh
International Journal of Pharmacology , 2010,
Abstract: The aim of this study was to investigate the myorelaxant and the spasmolytic effects of the Globularia alypum L. (GA) extract and to elucidate its role on the Ca2+ mobilization. Contraction of isolated rabbit jejunum incubated in Tyrode solution was recorded in presence of methanolic extract of GA. This extract showed a reduction of the amplitude and the tone of spontaneous contraction in a concentration-dependent manner. Spasmolytic effect was studied on tonus increase induced by Ach 10-5 M or by Tyrode high KCl (100 mM). Acetylcholine (10-5 M) induced contraction was inhibited by cumulative concentrations of the extract. Also, GA completely relaxed the jejunum contracted by KCl. In order to assess if GA effect involved Ca2+ influx restriction, the jejunum was replaced in Ca2+ free Tyrode solution with EDTA (2 mM) or in Tyrode containing GA (6.4 mg mL-1) and then was challenged with KCl or Ach. Pre-treatment with GA extract inhibited the restored spontaneous contraction obtained when Ca2+ was added to the bath. GA extract abolished tonic phase of Ach induced contraction and drastically diminished phasic one, while it completely abolished KCl induced contraction. Similar responses were obtained when the jejunum was placed in Tyrode Ca2+ free. Verapamil a standard spasmolytic agent or a sub maximal concentration of GA inhibited and right shifted the Ca2+ response curves realized on jejunum incubated in high K+ Ca2+ free. All these results suggest that GA extract probably acts at least through a voltage-dependent Ca2+ channels blockade.
Etude de la complexité de la gestion des espaces publics à vocation de transport à Dakar (Sénégal)
Cheikh Samba Wade,Rémy Tremblay,El Hadji Mamadou Ndiaye
études Caribeénnes , 2010, DOI: 10.4000/etudescaribeennes.4445
Abstract: L’organisation et de la gestion des espaces publics en milieu urbain est au centre des préoccupations de la puissance publique. Cet intérêt est lié dans les pays en développement aux nombreux dysfonctionnements recensés dans la ville. Ces difficultés entretenues par la démographie galopante, l’urbanisation informelle et à l’accroissement des activités industrielles, commerciales entre autres. A Dakar, la question de la mobilité urbaine est exacerbée par les puissants mouvements pendulaires entre la ville centrale et la périphérie amplifiés par les stationnements anarchiques et par l’inorganisation des modes de transports urbains.Le type d’espace public choisi pour cet article est une gare routière située au c ur du Plateau de Dakar : Petersen. Elle appara t comme l’une des plus importantes gares routières du pays, surtout en termes de fréquentation avec plus de 50 000 personnes par jour. Le mode de gestion appliqué ici est la concession, une convention par laquelle la puissance publique confie la gestion de l’équipement à la SAGES une structure privée prenant en charge les intérêts parfois très contradictoires des différents acteurs. The organization and management of public spaces in urban areas is a central concern of public authorities. This interest is linked in developing countries with numerous shortcomings identified in the city. These difficulties sustained by massive population growth, urbanization informal, and increased industrial activities, commercial and others. In Dakar, the question of urban mobility is exacerbated by the significant commuting between the city center and the periphery that are amplified by the chaotic parking lots and the disorganization of urban transport modes.The type of public space chosen for this article is a bus station in the heart of the Plateau de Dakar: Petersen. It appears as one of the largest bus stations in the country, especially in terms of attendance with over 50,000 people per day.The management method applied here is the concession, an agreement by which the public entrusts the management of equipment at the SAGES, a private organization that supports some very conflicting interests of different actors.
Problème de Cauchy avec des conditions modifiées pour les équations d'Euler-Poisson-Darboux
Cheikh Ould Mohamed El-hafed,Mohamed Vall Ould Moustapha
Physics , 2011,
Abstract: Nowadays the Euler-Poisson-Darboux equation is extensively studied in several settings. The main questions on avery spaces are explicit solutions for the classical Cauchy problems with the second data null. In this note we will generalize and unify several results on Euler-Poisson-Darboux equation. In this note we consider the Cauchy problem with modified conditions for the Euler-Poisson-Darboux equation. We give the explicit solutions in terms of Gauss 2F1 and Appel F4 hypergeometric functions with applications to the classical and radial wave equations
A Novel Decoder Based on Parallel Genetic Algorithms for Linear Block Codes  [PDF]
Abdeslam Ahmadi, Faissal El Bouanani, Hussain Ben-Azza, Youssef Benghabrit
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2013, DOI: 10.4236/ijcns.2013.61008
Abstract:

Genetic algorithms offer very good performances for solving large optimization problems, especially in the domain of error-correcting codes. However, they have a major drawback related to the time complexity and memory occupation when running on a uniprocessor computer. This paper proposes a parallel decoder for linear block codes, using parallel genetic algorithms (PGA). The good performance and time complexity are confirmed by theoretical study and by simulations on BCH(63,30,14) codes over both AWGN and flat Rayleigh fading channels. The simulation results show that the coding gain between parallel and single genetic algorithm is about 0.7 dB at BER = 105 with only 4 processors.

Emotion Evaluation of Four Generations of Woman from a 104-Year Old Ancestress  [PDF]
Gilles Sicard, Guy Escoffier, Elodie Salebert, Abdessadek El Ahmadi, Sadelli Kevin, Fran?ois S. Roman
World Journal of Neuroscience (WJNS) , 2018, DOI: 10.4236/wjns.2018.83028
Abstract: Normal aging is associated with declines of perception and cognition. Inversely, emotions seem to be preserved compared to younger adults. Viewing, neutral, dramatic and comic films, emotions were evaluated in four generations of woman from a 104-year old ancestress. At the very old age, from this case report, emotions were differently expressed while arousal was still preserved. A constant emotion of scare was expressed during the viewing of these three films (p < 0.001) with significant higher level of disgust (p 0.01). Only perceptual deficiency cannot explain this difference as cognitive tasks revealed a mild cognitive impairment detected by the Mini Mental State Examination and a substantial impairment on the executive functions by using the Delayed response tasks. These results emphasize that some emotions in a normal aging centenarian are still present, even if not appropriates, and different in comparison to a young adult control group. From this study, it is expected that emotion analysis in old adults viewing selected short films will predict longevity and could discriminate normal processes occurring during normal aging from neurodegenerative diseases.
Dipeptidyl peptidase IV (CD26) activity in the hematopoietic system: differences between the membrane-anchored and the released enzyme activity
Pereira, D.A.;Gomes, L.;El-Cheikh, M.C.;Borojevic, R.;
Brazilian Journal of Medical and Biological Research , 2003, DOI: 10.1590/S0100-879X2003000500003
Abstract: dipeptidyl peptidase iv (dpp-iv; cd26) (ec 3.4.14.5) is a membrane-anchored ectoenzyme with n-terminal exopeptidase activity that preferentially cleaves x-pro-dipeptides. it can also be spontaneously released to act in the extracellular environment or associated with the extracellular matrix. many hematopoietic cytokines and chemokines contain dpp-iv-susceptible n-terminal sequences. we monitored dpp-iv expression and activity in murine bone marrow and liver stroma cells which sustain hematopoiesis, myeloid precursors, skin fibroblasts, and myoblasts. rt-pcr analysis showed that all these cells produced mrna for dpp-iv. partially purified protein reacted with a commercial antibody to cd26. the km values for gly-pro-p-nitroanilide ranged from 0.43 to 0.98 mm for the membrane-associated enzyme of connective tissue stromas, and from 6.76 to 8.86 mm for the enzyme released from the membrane, corresponding to a ten-fold difference, but only a two-fold difference in km was found in myoblasts. km of the released soluble enzyme decreased in the presence of glycosaminoglycans, nonsulfated polysaccharide polymers (0.8-10 μg/ml) or simple sugars (320-350 μg/ml). purified membrane lipid rafts contained nearly 3/4 of the total cell enzyme activity, whose km was three-fold decreased as compared to the total cell membrane pool, indicating that, in the hematopoietic environment, dpp-iv activity is essentially located in the lipid rafts. this is compatible with membrane-associated events and direct cell-cell interactions, whilst the long-range activity depending upon soluble enzyme is less probable in view of the low affinity of this form.
IgE expression on the surface of B1 and B2 lymphocytes in experimental murine schistosomiasis
Oliveira, F.L.;Aguiar, A.M.;Borojevic, R.;El-Cheikh, M.C.;
Brazilian Journal of Medical and Biological Research , 2005, DOI: 10.1590/S0100-879X2005000700006
Abstract: in a previous study we monitored the distribution and phenotype expression of b1 cells during the evolution of experimental murine schistosomiasis mansoni and we proposed that the b1 cells were heterogeneous: a fraction which originated in the spleen and followed the migratory pathway to mesenteric ganglia, while the other was the resident peritoneal b1-cell pool. in the present study, we have addressed the question of whether these two b1-lymphocyte populations are involved in the production of the late ig isotype ige, which is present in high levels in schistosomal infection. lymphocyte expression of surface markers and immunoglobulins were monitored by immunofluorescence flow cytometry. both in the spleen and mesenteric ganglia, the b1 and b2 cells were induced to switch from igm to ige in the early th2-dominated phase of the disease, with an increase of ige in its later phases. conversely, peritoneal b1-igm+ switched to the remaining ige+ present in high numbers in the peritoneal cavity throughout the disease. we correlated the efficient induction of the expression of late ig isotypes by b1 cells with high levels of inflammatory cytokines due to the intense host response to the presence of worms and their eggs in the abdominal cavity. in conclusion, b1 cells have a different switch behavior from igm to ige indicating that these cell sub-populations depend on the microenvironment.
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