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Search Results: 1 - 10 of 554148 matches for " A Béchir "
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Facteurs de variation du poids vif et de l’état corporel du zébu Arabe en zone soudanienne du Tchad
A Béchir, P Grimaud, C Kaboré-Zoungrana
Sciences & Nature , 2010,
Abstract: L’objectif de cette étude a été de déterminer les effets saisonniers sur l’évolution du poids et de la note d’état corporel (NEC) des zébus arabes du Tchad. Durant les cinq saisons liées au calendrier fourrager, des mensurations et des notations d’état corporel ont été effectuées sur des bovins males et femelles. Les mesures barymétriques ont concerné le périmètre thoracique. La NEC a été déterminée par palpation de la région lombaire de l’animal. L’alternance saisonnière a provoqué de grandes variations de poids et de l’état corporel des animaux qui ont été notées selon le sexe et l’age. La variabilité des performances pondérales (2,2 ± 16 kg à 64 ±24 kg) et d’état corporel des animaux, obtenue à partir des facteurs individuels (sexe ou age) et saisonniers (disponibilité fourragère), a montré que ce sont les animaux d’age supérieur à 6 ans qui ont perdu plus de poids en saison sèche. Les femelles de 3-6 ans (64 ± 44,8 kg) et les males de 2-3 ans (54 ± 43 kg) ont montré les fluctuations pondérales les plus significatives en saison des pluies. Afin de minimiser les risques et maximiser la production en élevage extensif, des améliorations dans la conduite des animaux ont été proposées. Mots clés : Variations fourragères - Poids - Etat corporel - Zébu arabe - Tchad
Note on Bessel functions of type $A_{N-1}$
Béchir Amri
Mathematics , 2013,
Abstract: Through the theory of Jack polynomials we give an iterative method for integral formula of Dunkl-Bessel functions of type $A_{N-1}$ and a partial product formula for it.
On the integral representations for Dunkl kernels of type $A_{2}$
Béchir Amri
Mathematics , 2015,
Abstract: We give an explicit integral formula for the Dunkl kernel associated to root system of type $A_2$ and parameter $k>0$, by exploiting recent result in [1].
Riesz transform for Dunkl Hermite expansion
Béchir Amri
Mathematics , 2012,
Abstract: In the present paper, we establish that Riesz transforms for Dunkl Hermite expansion as introduced in [4] are singular integral operators with H\"ormander's type conditions and we show that are bounded on $L^p(\mathbb{R}^d; d\mu_k) 1 < p < 1.
Adsorption of F-, NO3- and SO42- on AFN Anionic Membrane: Kinetics and Thermodynamics Studies  [PDF]
Chiraz Hannachi, Fatma Guesmi, Wided Bouguerra, Bèchir Hamrouni
American Journal of Analytical Chemistry (AJAC) , 2013, DOI: 10.4236/ajac.2013.49064
Abstract:

The sorption of \"\" and \"\" from aqueous solution on AFN membrane has been studied and the equilibrium isotherms determined. The experimental data have been analyzed using the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models at different temperatures varying from 283 to 313 K. The results were analyzed using three kinetic models, Lagergen first order, second order and the Elovich model. The obtained results show that the best-fit correlation of the experimental data was obtained using the second order model. Thermodynamic parameters for the adsorption system were determined at 283, 298 and 313 K.

Boron Removal by Electrocoagulation Using Full Factorial Design  [PDF]
Khaoula Missaoui, Wided Bouguerra, Chiraz Hannachi, Béchir Hamrouni
Journal of Water Resource and Protection (JWARP) , 2013, DOI: 10.4236/jwarp.2013.59088
Abstract:

Saline waters treatment has become increasingly important for drinking water supply in a greater part of the world. However, some serious limitations had recently been discovered during water treatment, among them the boron problem seems to have a critical meaning. According to the WHO regulations (2011), the boron concentration should be reduced to less than 2.4 mg/L for drinking water. The purpose of this study is to investigate the feasibility of electrocoagulation (EC) as a pretreatment process to remove boron from saline waters. To optimize the experimental conditions of boron removal, the effects of some parameters were studied such as inter-electrode distance (die), electrode connection mode, (S/V) ratio, pHi and initial conductivity of the solution (σi). Subsequently, an experimental design methodology was implemented to evaluate statistically the most significant operating parameters. The effects of current density, EC time and initial boron concentration and their mutual interaction were investigated using 23 full factorial design. At optimal conditions, boron removal from synthetic aqueous solutions containing initial boron concentrations of 5 and 50 mg/L reached 81% and 79%, respectively. Applied to boron removal from seawater samples, EC reduces boron concentration to less to 2.4 mg/L with excessive energy consumption under optimal parameters.

Model of end stage liver disease (MELD) score greater than 23 predicts length of stay in the ICU but not mortality in liver transplant recipients
Christian E Oberkofler, Philipp Dutkowski, Reto Stocker, Reto A Schuepbach, John F Stover, Pierre-Alain Clavien, Markus Béchir
Critical Care , 2010, DOI: 10.1186/cc9068
Abstract: We retrospectively analyzed data of 144 consecutive liver transplant recipients over a 72-month period in our transplant unit, from January 2003 until December 2008 and performed uni- and multivariate analysis for morbidity and mortality, in particular to define the influence of MELD to these parameters.This study identified MELD score greater than 23 as an independent risk factor of morbidity represented by intensive care unit (ICU) stay longer than 10 days (odds ratio 7.0) but in contrast had no negative impact on mortality. Furthermore, we identified transfusion of more than 7 units of red blood cells as independent risk factor for mortality (hazard ratio 7.6) and for prolonged ICU stay (odds ratio [OR] 7.8) together with transfusion of more than 10 units of fresh frozen plasma (OR 11.6). Postoperative renal failure is a strong predictor of morbidity (OR 7.9) and postoperative renal replacement therapy was highly associated with increased mortality (hazard ratio 6.8), as was hepato renal syndrome prior to transplantation (hazard ratio 13.2).This study identified MELD score greater than 23 as an independent risk factor of morbidity represented by ICU stay longer than 10 days but in contrast had no negative impact on mortality. This finding supports the transplantation of patients with high MELD score but only with knowledge of increased morbidity.Liver transplantation is still a complex and cost-intensive procedure [1] and the results are influenced by many interrelated factors. As liver transplantation has become a universally accepted treatment for end-stage liver disease, the number of patients accumulating on the waiting list has gradually outweighed the scarce resources of available organs. Fair allocation of donor livers to patients with end-stage liver disease is a difficult task. The USA and Europe used prioritization systems based on waiting time and on the parameters of the Child-Turcotte-Pugh score [2]. Since February 2002, the United Network for Organ
Noninvasive cardiac output and blood pressure monitoring cannot replace an invasive monitoring system in critically ill patients
John F Stover, Reto Stocker, Renato Lenherr, Thomas A Neff, Silvia R Cottini, Bernhard Zoller, Markus Béchir
BMC Anesthesiology , 2009, DOI: 10.1186/1471-2253-9-6
Abstract: Nexfin HD is a continuous noninvasive blood pressure and cardiac output monitor system and is based on the development of the pulsatile unloading of the finger arterial walls using an inflatable finger cuff. During continuous BP measurement CO is calculated. We included 10 patients with standard invasive cardiac monitoring system (pulmonary artery catheter and arterial catheter) comparing invasively obtained data to the data collected noninvasively using the Nexfin HD.Correlation between mean arterial pressure measured with the standard arterial monitoring system and the Nexfin HD was r2 = 0.67 with a bias of -2 mmHg and two standard deviations of ± 16 mmHg. Correlation between CO derived from PAC and the Nexfin HD was r2 = 0.83 with a bias of 0.23 l/min and two standard deviations of ± 2.1 l/min; the percentage error was 29%.Although the noninvasive CO measurement appears promising, the noninvasive blood pressure assessment is clearly less reliable than the invasively measured blood pressure. Therefore, according to the present data application of the Nexfin HD monitoring system in the ICU cannot be recommended generally. Whether such a tool might be reliable in certain critically ill patients remains to be determined.Cardiovascular monitoring is a standard procedure in critical care medicine. Traditionally invasive techniques like pulmonary artery catheter (PAC) and peripheral artery catheters are widely used [1-3]. A further possibility of cardiovascular monitoring is the PiCCO system[4]. These techniques are well established and validated [5-7]. Besides the advantages of these invasive techniques for clinical decision-making, these methods both bear the risks of deleterious complications as e.g., bleeding, pneumothorax and infection; PAC is also associated with the risk of inducing pulmonary artery rupture [8,9]. Furthermore, these systems are cost intensive. Nexfin HD is a continuous noninvasive blood pressure (BP) and cardiac output (CO) monitor (former called
Riesz transforms for Dunkl transform
Béchir Amri,Mohamed Sifi
Mathematics , 2011,
Abstract: In this paper we obtain the $L^p$-boundedness of Riesz transforms for Dunkl transform for all $1
Thromboelastography to Monitor Clotting/Bleeding Complications in Patients Treated with the Molecular Adsorbent Recirculating System
Esther B. Bachli,J?rg B?siger,Markus Béchir,John F. Stover,Reto Stocker,Marco Maggiorini,Eberhard L. Renner,Beat Müllhaupt,Reto A. Schuepbach
Critical Care Research and Practice , 2011, DOI: 10.1155/2011/313854
Abstract: Background. The Molecular Adsorbent Recirculating System (MARS) has been shown to clear albumin-bound toxins from patients with liver failure but might cause bleeding complications potentially obscuring survival benefits. We hypothesized that monitoring clotting parameters and bed-side thromboelastography allows to reduce bleeding complications. Methods. Retrospective analysis of 25 MARS sessions during which clotting parameters were monitored by a standardized protocol. Results. During MARS therapy median INR increased significantly from 1.7 to 1.9 platelet count and fibrinogen content decreased significantly from 57?fL?1 to 42?fL?1 and 2.1?g/L to 1.5?g/L. Nine relevant complications occurred: the MARS system clotted 6 times 3 times we observed hemorrhages. Absent thrombocytopenia and elevated plasma fibrinogen predicted clotting of the MARS system (ROC 0.94 and 0.82). Fibrinolysis, detected by thromboelastography, uniquely predicted bleeding events. Conclusion. Bed-side thromboelastography and close monitoring of coagulation parameters can predict and, therefore, help prevent bleeding complications during MARS therapy. 1. Introduction Due to limited donor liver availability, only selected patients with acute or acute-on-chronic liver failure profit from liver transplantation [1]. The majority of patients receive supportive therapy, and mortality remains high [2]. Various artificial liver support systems have been developed and proposed as bridging therapy until liver function recovers or a donor organ becomes available [3]. The Molecular Adsorbent Recirculating System (MARS), a cell-free albumin dialysis device, has been shown to remove albumin bound compounds and toxins and to exert a number of beneficial hemodynamic effects in patients with acute and acute-on-chronic liver failure [4]. However, to date, neither MARS nor any other liver support system has been unequivocally proven to alter clinical outcomes such as survival, a conclusion based on a meta-analysis [5] and yet unpublished multicenter clinical trials (HELIOS study, RELIEF trial; European Association for the Study of the Liver 2010). Bleeding disorders are a major concern in all patients with liver failure [6]. MARS involves an extracorporeal blood circuit through a filter. This can lead to activation of platelets and the coagulation system [7]. Recent reports describe an association of severe and potentially fatal bleeding complications with MARS therapy [8–10]. Patients’ age, vasopressor therapy, pretreatment INR, fibrin D-dimer and fibrinogen concentrations [8], factor VIII, von
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