Sfax, Tunisia
Sfax, Tunisia

The University of Sfax is a university located in Sfax, Tunisia. It was founded in 1986 and is organized in 8 Faculties.The University of Sfax is a university based in Sfax .It was founded in 1986 under the name University of the South and then covers all academic institutions in the South. It is divided into three universities, including the current University of Sfax, with the creation of the University of Gabes in 2003 and the University of Gafsa in 2004. Wikipedia.

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Kchaou H.,University of Sfax | Karoui K.,University of Sfax | Rhaiem A.B.,University of Sfax
Physica E: Low-Dimensional Systems and Nanostructures | Year: 2017

The X-ray powder diffraction patterns shows that at room temperature [N(CH3)3H]CdCl3 crystallizes in the orthorhombic system with the Pbnm space group. The analysis of the data revealed the existence of optical allowed direct transition mechanisms with the band gap energy equal to 5.3 eV. The temperature dependences of the real part of dielectric permittivity show a relaxation process at high temperature that can be explained by the reorientational motion of alkyl chains. The alternative current (AC) electrical conduction in compound is governed by three processes, which can be attributed to several models: the correlated barrier hopping (CBH) model in phases I and II, the non-overlapping small polaron tunneling (NSPT) model in phases III and IV. © 2016 Elsevier B.V.

Haj Brahim I.,University of Sfax | Chaabane M.,University of Sfax | Mehdi D.,University of Poitiers
International Journal of Fuzzy Systems | Year: 2017

This paper focuses on the robust sensor fault-tolerant control of T–S fuzzy descriptor systems with unmeasurable premise variables subject to external disturbances. By introducing sensor fault as an auxiliary state vector, an augmented fuzzy descriptor system is constructed. A robust fuzzy descriptor observer is investigated to achieve simultaneous reconstruction of system states and sensor faults using descriptor approach and the L2 techniques to minimize the effect of the perturbations on the state estimation error. Based on the state estimated variables and by isolating the sensor fault, a fault-tolerant control scheme is proposed using a state feedback controller approach such that the resulting closed-loop system is stable with prescribed H∞ performance. Sufficient conditions for the existence of a robust fuzzy descriptor observer and a fault-tolerant controller are derived in the sense of Lyapunov asymptotic stability and are formulated in terms of a series of linear matrix inequalities without additional constraints. Finally, a numerical example was discussed to prove the performance of the proposed approach. © 2016, Taiwan Fuzzy Systems Association and Springer-Verlag Berlin Heidelberg.

Salhi H.,University of Sfax | Kamoun S.,University of Sfax
International Journal of Modelling, Identification and Control | Year: 2017

The paper deals with the parameter estimation problem of Wiener state-space models with hysteresis-saturation nonlinearities. A recursive parametric and state estimation algorithm is presented for the Wiener system by combining the adjustable model idea, the least squares technique and the Kalman filter principle. The basic idea is to decompose the hysteresis-saturation nonlinearity into two asymmetric saturation nonlinearities and to estimate jointly the state variables, the parameters and the internal variable of the considered Wiener model using the available input-output data. The proposed recursive algorithm can be extended to nonlinear systems with other hard nonlinearities. © 2017 Inderscience Enterprises Ltd.

Zn–Mn alloy electrodeposition on steel electrode in chloride bath was investigated using cyclic voltammetric, chronopotentiometric and chronoamperometric techniques. Cyclic voltammetries (CV) reveal a deep understanding of electrochemical behaviors of each metal Zn, Mn, proton discharge and Zn–Mn co-deposition. The electrochemical results show that with increasing Mn2+ ions concentration in the electrolytic bath, Mn2+ reduction occurs at lower over-potential leading to an enhancement of Mn content into the Zn–Mn deposits. A dimensionless graph model was used to analyze the effect of Mn2+ ions concentration on Zn–Mn nucleation process. It was found that the nucleation process is not extremely affected by Mn2+ concentration. Nevertheless, it significantly depends on the applied potential. Several parameters such as Mn2+ ions concentration, current density and stirring were investigated with regard to the Mn content into the final Zn–Mn coatings. It was found that the Mn content increases with increasing the applied current density jimp and Mn2+ ions concentration in the electrolytic bath. However, stirring of the solution decreases the Mn content in the Zn–Mn coatings. The phase structure and surface morphology of Zn–Mn deposits are characterized by means of X-ray diffraction analysis and Scanning Electron Microscopy (SEM), respectively. The Zn–Mn deposited at low current density is tri-phasic and consisting of η-Zn, ζ-MnZn13 and hexagonal close packed ε-Zn–Mn. An increase in current density leads to a transition from crystalline to amorphous structure, arising from the hydroxide inclusions in the Zn–Mn coating at high current density. © 2017

Rahman S.,National University of Malaysia | Marzuki M.A.,University of Sfax
Advanced Science Letters | Year: 2017

‘Children not interested to learn,’ ‘easily feel bored of learning’ and ‘having difficulty in understanding complex health knowledge’ are among issues in childhood education. This paper discusses the effect of applying the humanistic learning theory on experiences and learning patterns of children. The strategy of the “child friendly” concept, which is guided by the concept in Carl Rogers’s learning theory, is applied in the children’s learning environment that involves 68 children from ages 3 to 6 years and implemented over a period of 32 weeks in a nursery school. The “child friendly” environment refers to a learning environment, which comprises learning notes and activities with special characteristics that are well liked by and suitable for children as well as providing a learning environment that attracts the interest of children towards learning health issues. The data on children’s experiences and learning patterns were collected from video recordings, observations and anecdotal records throughout the implementation of the program and analysed using ATLAS.ti. The findings showed that the “child friendly” concept strategy that was guided by the humanistic learning theory applied in the children’s learning environment had a positive effect on experiences and learning patterns that ‘elated’ (94.29%), ‘excited’ (90.02%), was ‘accepted’ (98.59%), and ‘appreciated’ (95.71%) by the children. In conclusion, the findings support the “child friendly” concept that was guided by the humanistic learning theory and used in the teaching-learning process of children from ages 3 to 6 years in order to determine experiences and learning patterns such as ‘elation,’ ‘excitement,’ ‘acceptance’ and ‘appreciation.’ This subsequently enhanced children’s motivation to continue learning without feeling bored. © 2017 American Scientific Publishers All rights reserved.

Hakim H.,University of Sfax | Sellami A.,University of Sfax | Ben Abddallah H.,King Abdulaziz University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2017

Paying attention to authenticity, as a security requirement, in the early phases of the software life-cycle (such as requirement and-or design) can save project cost, time, and effort. However, in the ISO 25010 quality model which describes quality sub-characteristics, authenticity measures are not explicitly described, neither are they documented with sufficient details. This paper proposes a clear and precise way of measuring the “authenticity” sub-characteristic based on structural and functional size measurements. This combination can be used to identify the risk of authenticity violation in the design phase. An example of Facebook Web User Authentication is used to illustrate our proposed measurement. © Springer International Publishing AG 2017.

Dahech K.,University of Sfax | Allouche M.,University of Sfax | Damak T.,University of Sfax | Tadeo F.,University of Valladolid
Electric Power Systems Research | Year: 2017

In this paper, a fast and efficient maximum power point tracking (MPPT) control for a photovoltaic (PV) system is developed based on both backstepping and sliding mode approaches. The considered PV system consists of a PV module supplying, through a DC converter, a resistive load. The control scheme includes two loops. The first loop, estimates the maximum power voltage (MPV) which is used in the second loop as a reference value for backstepping sliding mode control (BSMC). The proposed BSMC-based controller forces the PV system to operate very close to the maximum power point (MPP) by adjusting the duty cycle of the DC–DC boost converter. This approach presents a good transition response, a low tracking error and a very fast reaction against solar irradiation variations. To show the effectiveness of the developed control scheme a comparative study is presented with the terminal sliding mode control (TSMC) approach. © 2016 Elsevier B.V.

Ali S.,University of Sfax | Baccar M.,University of Sfax
Applied Thermal Engineering | Year: 2017

This study deals with numerical simulations of the hydrodynamic and thermal behaviors in scraped surface heat exchanger (SSHE) which includes helical ribbon instead of scraper blades. A three-dimensional resolution of the conservation equations of continuity, momentum and energy was conducted using a specific CFD code based on the finite volume method. Laminar, steady-state and non-isothermal flow of Bingham fluids, characterized by high viscosity, were investigated. The conjugated effect of rotational and axial Reynolds numbers on the hydrodynamic and thermal behaviors is studied. Increasing the ratio of rotational Reynolds to axial Reynolds numbers improves scraping surface frequency and consequently, the tube-side heat transfer coefficients are enhanced. Simultaneously, the back-mixing phenomenon becomes more important and reduces the temperature driving force for heat transfer. Moreover, the influence of Oldroyd number on the velocity and temperature fields, the apparent viscosity and rigid zones is established. The numerical results have shown that increasing the Oldroyd number reduces recirculation zones and improves slightly the heat transfer. In this work, the determination of correlation is presented using a dimensionless analysis method in order to predict the heat transfer coefficient within SSHE in the case where the ratio of rotational to axial Reynolds numbers is inferior to 1. © 2016 Elsevier Ltd

Baati R.,University of Sfax | Magnin A.,French National Center for Scientific Research | Boufi S.,University of Sfax
ACS Sustainable Chemistry and Engineering | Year: 2017

Cellulose nanofibrils (CNFs) with a high solid content of 10% were produced from oxidized holocellulose pulps by continuous extrusion using a twin-screw minicompounder in replacement of the high pressure homogenization or grinding, conventionally used to produce CNFs. A strong gel with high yield in nanofibrillated material exceeding 80% was obtained after 30 min of recirculation through the extruder at room temperature. The effect of the chemical composition of the pulp and the carboxyl content on the fibrillation yield and the properties of the ensuing CNFs were investigated. CNF material with a lateral dimension lower than 5 nm and a length within the micrometer scale was produced through this simple approach, and no evolution in crystallinity in terms of crystalline indexes was observed after prolonged extrusion up to 30 min. Dynamical rheology showed that the CNF suspension exhibited an elastic gel-like behavior over the whole concentration domains, ranging from 1 to 10% w/w. The described preparation method is easy to implement, without any clogging risk during the disintegration process and can be scaled up for a high capacity and cost-effective production of CNFs at high consistency. © 2017 American Chemical Society.

A series of 2%Eu3+-activated ALnP2O7 (A = Rb, Cs, Tl; Ln = Y, Lu, Tm) pyrophosphates were synthesized via solid-state reaction method and characterized by X-ray diffraction (XRD), NMR and IR/Raman spectroscopy. Their photoluminescence properties were investigated at room temperature. The phosphors present red emitting luminescence under blue light excitation, based on f–f transitions of Eu3+ ions. Emission spectra showed that the samples had intense and prevailing red emissions at 610 nm belonging to the 5D0→7F2 electric dipole transition. One Eu3+ center was assigned according to the crystal structure and the luminescence characteristics. The decay times were measured monitoring the maximum of emission at λem = 610 nm and exciting in the 5D2 band (λexc = 464 nm). All decay curves were single exponential and lifetimes remain constant with value in integral range 3–4 ms, according to the alkali metal ion. The optical properties show that these host materials are suitable for phosphor materials for solid-state lighting applications. © 2017 Elsevier B.V.

Cote L.,Laval University | Cote L.,University of Sfax | Rocque R.,Laval University | Audetat M.-C.,University of Geneva
Patient Education and Counseling | Year: 2017

Objectives: Supervision of communication competency in clinical settings in medicine is an important component of professional training. The purpose of this study was to describe the content and rationale of psychology and social work preceptor feedback to family medicine residents who express educational needs during case-based written vignettes. Methods: We conducted a qualitative study with 25 psychology and social work preceptors from family medicine departments of the three French-speaking universities in the province of Quebec, Canada. During an individual interview, preceptors were asked to respond to three short case-based written vignettes depicting resident educational issues regarding communication and to explain their responses. Authors analyzed the content of responses and the conceptual frameworks reported. Results: The three vignettes elicited 475 responses, including 58 distinct responses and 33 distinct conceptual frameworks. Therapeutic alliance and stages of grief were the two most reported conceptual frameworks. Conclusion: The vignettes stimulated a wealth of responses and conceptual frameworks among psychology and social work preceptors in family medicine. Practical implications: The complete list of responses could be useful for faculty development activities by stimulating preceptors' reflexive practice with regard to their responses, the educational goals of these responses and the conceptual frameworks underlying their feedback. © 2017 Elsevier B.V.

Touir J.,University of Sfax | Mechi C.,University of Sfax | Haj Ali H.,University of Sfax
Journal of African Earth Sciences | Year: 2017

In Tunisia the Cenomanian-Turonian boundary coincides with the transition between two carbonate deposits: the Late Cenomanian Bahloul Formation at the bottom and the Early Turonian Gattar Member at the top. According to field study and microscope examination of the studied Formations throughout Tunisia, the Bahloul Formation consists of a deep-water condensed carbonate platform largely extended throughout Tunisia. Detailed analysis shows a particular richness in planktonic microfauna and ammonites. Thin bedded limestones within the Upper part exhibits a high TOC ratio and commonly called the black shales, whereas the Gattar Member displayed a rudist-bearing carbonate ramp which pinches northward while being progressively relayed by hemipelagic marls forming the so-called Annaba Member. The Cenomanian-Turonian transition was marked by relevant changes the main features of which are well recorded in the Tunisian carbonate platform. The changes consist of consecutive (i) shutdown and recovery of the carbonate factory and (ii) extinction, development and diversification of many faunal species. As matter of fact, during Late Cenomanian many planktonic foraminifers (Rotaliporidae) and rudists (Caprinidae) were extinct, and simultaneously the carbonate production rate fallen into 0.003–0.017 m k y −1. During Early Turonian the carbonate platform recovered contemporaneously with the development and diversification of many planktonic foraminifera and rudists (Hippuritidae); the carbonate productivity rose to 0.125 m k y −1 in average. The whole previous changes are to be linked with the significant sea-level fluctuation and the contemporaneous oceanic anoxic event (OAE2) having occurred at the Cenomanian-Turonian boundary. © 2017

Affouri H.,University of Sfax | Sahraoui O.,University of Sfax
Journal of African Earth Sciences | Year: 2017

The vertical distributions of bulk and molecular biomarker composition in samples from a ca. 156 cm sediment core from Lake Ichkeul were determined. Bulk analysis (Rock-Eval pyrolysis, carbonate, lipid extraction) and molecular analysis of saturated fractions were used to characterize the nature, preservation conditions and input of sedimentary organic matter (OM) to this sub-wet lake environment. The sediments are represented mainly by gray-black silty-clay facies where the carbonate (CaCO3) content varies in a range of 10–30% dry sediment. Rock-Eval pyrolysis revealed a homogeneous total organic carbon (TOC) content of ca. 1% sediment, but with down core fluctuation, indicating different anoxic conditions at different depths and material source variation. The values show three periods of relative enrichment, exceeding ca. 1%, at 146-134 cm, 82 cm and 14-0 cm depth. The low Hydrogen Index (HI) values [<119 mg hydrocarbon (HC)/g TOC)] were characteristic of continental Type III OM. The Tmax values in the range 415–420 °C were characteristic of immature OM at an early diagenetic stage. The distributions of n-alkanes (C17 to C34), isoprenoid (iso) alkanes (pristane and phytane), terpanes and steranes showed that the OM is a mixture of marine algal and bacterial source and emergent and floating higher plant origin. In addition, the distributions, as well as several biomarker ratios (n-alkanes, iso-alkanes/n-alkanes), showed that the OM is a mixture of immature and mature. Significant downcore fluctuation was observed in the molecular composition. This indicates intense microbial activity below ca. 50 cm core depth under an anoxic and brackish environment. © 2017 Elsevier Ltd

Ayed A.B.,University of Sfax | Halima M.B.,University of Sfax | Alimi A.M.,University of Sfax
Advances in Intelligent Systems and Computing | Year: 2017

Cluster forests is a novel approach for ensemble clustering based on the aggregation of partial K-means clustering trees. Cluster forests was inspired from random forests algorithm. Cluster forests gives better results than other popular clustering algorithms on most standard benchmarks. In this paper, we propose an improved version of cluster forests using fuzzy C-means clustering. Results shows that the proposed Fuzzy Cluster Forests system gives better clustering results than cluster forests for eight standard clustering benchmarks from UC Irvine Machine Learning Repository. © Springer International Publishing AG 2017.

Sayahi I.,University of Sfax | Elkefi A.,University of Sfax | Ben Amar C.,University of Sfax
Advances in Intelligent Systems and Computing | Year: 2017

During the last decade, the flow of 3D objects is increasingly used everywhere. This wide range of applications and the necessity to exchange 3D meshes via internet raise major security problems. As a solution, we propose a blind watermarking algorithm for 3D multi-resolution meshes ensuring a good compromise between invisibility, insertion rate and robustness while minimizing the amount of memory used during the execution of our algorithm. To this end, spiral scanning method is applied. It decomposes the mesh into GOTs (a Group Of Triangles). At each time, only one GOT will be loaded into memory to be watermarked. It undergoes a wavelet transform, a modulation then embedding data. Once finished, the memory will be released to upload the next GOT. This process is stopped when the entire mesh is watermarked. Experimental tests showed that the quality of watermarked meshes is kept despite the high insertion rate used and that memory consumption is very reduced (until 24% of memory reduction). As for the robustness, our algorithm overcomes the most popular attacks in particular compression. A comparison with literature showed that our algorithm gives better results than those recently published. © Springer International Publishing AG 2017.

Ben Hamad Bouhamed S.,University of Sfax | Kechaou N.,University of Sfax
Bioprocess and Biosystems Engineering | Year: 2017

Poultry feather keratin is the most important by-product from the poultry industry due to its abundance. Different methods have been still applied to process this by-product such as enzymatic hydrolysis which is expensive and inapplicable at the industrial level. This paper presents a study of acid hydrolysis of poultry feathers using different types of acids, sulphuric acid concentration, different temperatures and solid to liquid ratio to obtain a liquid product rich in peptides. The feathers analysis revealed a crude protein content of 88.83%. A maximum peptides production of 676 mg/g was reached using sulphuric acid, 1 molar acid concentration and 50 g/l solid to liquid ratio at a temperature of 90 °C after 300 min. A reaction scheme for protein aggregation and decomposition to polypeptides and amino acids was proposed and a kinetic model for peptides production was developed. The proposed kinetic model proved to be well adapted to the experimental data with R2 = 0.99. © 2017 Springer-Verlag Berlin Heidelberg

Khalladi A.,University of Sfax | Elleuch K.,University of Sfax
Journal of Tribology | Year: 2017

The objective of this study was to investigate the influence of contaminants on the tribological behavior of wheel-rail contact. Sand, phosphate, sulfur, and cement were the studied contaminants identified after a Tunisian railway expertise. All friction tests under different contaminants were conducted using pin-on-disk machine, maintaining the same sliding velocity and Hertzian pressure, respectively, at 0.1 m/s and 1000 MPa. All results were compared with reference of two configuration contacts: wheel tread-rail head (clean dry condition) and wheel flange-rail gauge (clean lubricated condition). The main findings of this study could be listed as follows. First, with reference to clean and dry condition tests, sand and cement showed a higher adhesion than phosphate and sulfur. Second, all contaminants increased the adhesion coefficient with reference to clean and lubricated conditions. Third, sulfur generated the lowest energy-wear coefficient yielding a mild wear. Fourth, sand, cement, and phosphate generated a higher energy-wear coefficient yielding an abrasive wear. Finally, the highest energy-wear coefficient was obtained with sand. © 2016 by ASME.

Diplectanid monogeneans are gill parasites that can infect fish in huge numbers and thus become harmful, especially in maricultured fish. It is therefore useful to have taxonomic tools, such as keys, to identify species. The following diplectanid species from groupers of the Mediterranean Sea were studied: five species of Pseudorhabdosynochus Yamaguti, 1958, including P. riouxi (Oliver, 1986) Kritsky & Beverley-Burton, 1986 from the dusky grouper Mycteroperca marginata, P. enitsuji Neifar & Euzet, 2007, P. bouaini Neifar & Euzet, 2007, P. dolicocolpos Neifar & Euzet, 2007 and P. sinediscus Neifar & Euzet, 2007 from the goldblotch grouper M. costae, and Echinoplectanum echinophallus (Euzet & Oliver, 1965) Justine & Euzet, 2006 from the dusky grouper. New material was obtained from fish collected from off Tunisia and Libya and compared to the type-material and voucher specimens in museum collections. Identifications of fish were confirmed by barcoding of cytochrome c oxidase subunit I (COI) sequences. The sclerotized vagina was considered the most important structure for systematics. The three species P. riouxi, P. bouaini, and P. enitsuji share a common general structure of the sclerotized vagina with a conspicuous spherical secondary chamber. We thus propose the 'Pseudorhabdosynochus riouxi group' to accommodate them. Pseudorhabdosynochus dolicocolpos has an elongate vaginal structure that is completely different from all its congeneric species reported from the Mediterranean Sea, and Pseudorhabdosynochus sinediscus has a sclerotized vagina in which the secondary chamber is not visible, and a haptor without squamodiscs. A taxonomic key to diplectanid species on Mycteroperca spp. in the Mediterranean Sea is proposed; it includes ten species of Pseudorhabdosynochus and one species of Echinoplectanum. © 2017 Chaabane et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Ammar S.,University of Monastir | Hammami M.,University of Sfax | Ismail H.,University of Sfax
Mathematical Methods in the Applied Sciences | Year: 2017

The main purpose of this paper is to construct sign-changing solution for the following Neumann problem: (Formula presented.) where n≥3 and K is a bounded and continuous function on ℝn-1, which concentrate around two critical points satisfying some conditions. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Naumovic M.,University of Niš | Roganovic S.,University of Sfax
IFMBE Proceedings | Year: 2017

The human cardiovascular-respiratory system is a complex system which exhibits the properties of a control system of the regulator type. The gas exchange combines many processes that occur in the brain, lungs, vasculature, and body tissues. This paper deals with a simple model that provides a linearized description of pulmonary ventilation mechanics. Some equations describing the introduction to chemical regulation of lung ventilation are derived. © Springer Nature Singapore Pte Ltd. 2017.

Ammar O.,University of Sfax | Haddar N.,University of Sfax | Dieng L.,IFSTTAR
Intermetallics | Year: 2017

Pseudoelastic NiTi based shape memory alloys (SMA) wires have a good potential in civil engineering applications and often used as dampers in anti-seismic or cable structures when a rate varied cyclic loadings is applied. In accordance with these applications, an experimental characterization of NiTi wires under strain- and stress-controlled cyclic loadings at various strain rates is presented. Based on these loadings, it is shown that the stress–strain response of the material evolves up to a complete stabilization with the increase of the number of cycles. This evolution is accompanied with the degeneration of pseudoelasticity and transformation ratcheting in the case of strain- and stress-controlled mode, respectively. Also, it was found that the cyclic deformation of pseudoelastic NiTi SMA is significantly rate dependent. © 2017 Elsevier Ltd

Rouabeh H.,University of Sfax | Abdelmoula C.,University of Sfax | Masmoudi M.,University of Sfax
Proceedings of the International Conference on Microelectronics, ICM | Year: 2017

In this work, we propose a new approach for the connected component labeling task. The developed algorithm is based on a forward and backward scan of the image; from left to right and right to left and row by row. This approach takes into account the eight neighbors of the considered pixel. Unlike other algorithms that need to resolve equivalences in a second scan, with our approach we obtain at the end of the first scan an arranged table of resolved equivalent labels for each object. Another advantage of this method that a small number of labels may be required even for complicated objects. The second scan is done only to replace equivalent labels with the same representative label. These advantages make the approach more robust and sophisticated for many form recognition applications specifically for traffic signs identification which is our research subject. The software implementation of the method was firstly done using MATLAB and performances were evaluated. The simple formulation of the proposed method has enhanced the design of the VHDL circuit which is developed to be implanted on an FPGA card as part of a complete recognition system, and presented in this paper. © 2016 IEEE.

Mokni R.,University of Sfax | Kherallah M.,University of Sfax
International Journal of Biometrics | Year: 2016

Palmprint is a human physiological feature which can distinguish and identify one person from another. In the palmprint recognition biometric systems, the feature extraction is considered as the most important step. In this paper, we use the fractal approach which is both a very advanced and sophisticated method in order to extract the palmprint texture information features. This approach has been widely used in recent years being considered as an active research area in the image processing field. Therefore, we have implemented a new technique to extract the palmprint texture features: the texture analysis basing on the fractal dimension estimated via the box-counting method or TAFD-BC. Experimental results on the PolyU 2D Palmprint database prove that our proposed approach produces promising and favourable results compared to other well-known state-of-the-art techniques. Copyright © 2016 Inderscience Enterprises Ltd.

Walha I.,University of Sfax | Dhahri E.,University of Sfax
Journal of Alloys and Compounds | Year: 2017

Structural, magnetic and electrical measurements were performed to examine the effect of the silver substitution in the lanthanum sites on the physical properties. X-ray diffraction data have been analyzed by Rietveld and show no structural changes induced by Ag doping. Magnetization versus temperature studies have shown that all samples exhibit a magnetic transition from ferromagnetic to paramagnetic phase when temperature is increased. Two transitions (Tρ1 and Tρ2) are observed in the electrical resistivity, the second transition in the resistivity can be attributed to an abnormality characteristic of charge ordering (CO) effect. The electrical resistivity was described by a phenomenological percolation model. The MR increases with increasing applied magnetic field and decreases with the Ag substitution. At room temperature, the magnetorresistance (MR) for lanthanum substitution is about 40% and 55% for the parent compound at a magnetic applied field of 8 T. © 2016 Elsevier B.V.

Hammouda N.G.,Higher Institute of Computer and Communication Technologies of Hammam Sousse | Haddar K.,University of Sfax
Communications in Computer and Information Science | Year: 2016

Automatic annotation for Arabic corpora has an important role in many applications of Natural Language Processing (NLP). In this context, we are interested in the automatic annotation of Arabic corpora using transducers set implemented in NooJ platform. And to achieve our aim, we must precede the annotation phase by a segmentation phase. This segmentation phase will, on the one hand, reduce the complexity of the analysis and, on the other hand, improve NooJ platform functionalities. Also, we achieved our annotation phase by identifying different types of lexical ambiguities, and then an appropriate set of rules is proposed. In addition, we experiment our phase on a test corpus with NooJ platform. The obtained results are ambitious and can be improved by adding other rules and heuristics. © Springer International Publishing AG 2016.

Cheikhrouhou H.,University of Sfax | Cheikhrouhou H.,University of Franche Comte
Communications in Computer and Information Science | Year: 2016

Based on the dictionary of French verbs LVF of Jean Dubois and Françoise Dubois-Charlier, we propose to study the class of auxiliaries X. In this article, we try to translate the verbs of this class into Arabic while comparing the way French and Arabic verbal systems operate. We are going to integrate the verbs of the auxiliary class X (212 entries) into NooJ platform for an automatic translation and we will discuss the similarities as well as the differences between both verbal systems. © Springer International Publishing AG 2016.

Tounsi S.,University of Sfax
International Journal of Modelling and Simulation | Year: 2017

In this paper, we present a design and control methodology of an innovated structure of switching synchronous motor with reduced production cost. The control strategy is based on the pulse width modulation technique imposing currents sum of a continuous value and a value having a shape varying in phase opposition with respect to the variation of the inductances. This control technology can greatly reduce vibration of the entire system due to the strong fluctuation of the torque developed by the engine, generally characterizing switching synchronous motors. A systemic design and modeling program is developed. This program is validated following the implementation and the simulation of the control model in the simulation environment Matlab-Simulink. Simulation results are with good scientific level and encourage subsequently the industrialization of the global system. © 2017 Informa UK Limited, trading as Taylor & Francis Group

Masmoudi N.,University of Sfax | Soussi H.,University of Sfax | Krichen A.,University of Sfax
International Journal of Advanced Manufacturing Technology | Year: 2017

In this work, the flanged hole is adopted as a potential solution to increase the number of formed threads in the case of sheet metal part. To achieve an adequate initial tap hole for tapping process, the final shape of the flanged hole was analyzed by 2D finite element (FE) simulations. An adequate range of the clearance j between the die and the punch of the hole-flanging process was identified for which formed threads are performed on a vertical flange with more substantial and uniform thickness as well as an important height. To ensure that the selected flange is free from fracture, 3D FE model was developed using Gurson-Tvergaard-Needleman coupled approach. Experiments were carried out in order to validate the numerical results and to analyze the geometry of formed threads performed on the selected flanged hole and the drilled hole. © 2017 Springer-Verlag London

Ahmedou M.,Justus Liebig University | Ben Ayed M.,University of Sfax
Advanced Nonlinear Studies | Year: 2017

We consider the following Liouville-type equation on domains of ℝ2 under Dirichlet boundary conditions: {-Δu = σKeu/ΩKeu in Ω u=0 on ∂Ω where σ ϵ ℝ and K is a smooth nonnegative function having N zeros q1,...,qN, which takes in a neighborhood of a zero qj the following form: K(x)=Kj(x)|x -qj|2j with Kj(x)>0 and i ϵℝ such that 0

Saada F.B.,University of Sfax | Elleuch K.,University of Sfax
Mechanics and Industry | Year: 2017

Failure of equipment for processing olives interrupted oil production after only three weeks due to tribocorrosive wear of stainless steel components. Tribological behavior of 304 L stainless steel sliding against 52 100 steel was determined using a pin on disc tester. Tribological tests have shown that both normal load and rotating speed have a distinct effect on friction and wear behavior of the studied steel. An abrasive wear mechanism and plastic deformation of stainless steel on the wear track were investigated via an optical microscopy analysis. The concept of dissipated energy showed a significant correlation between the mass loss and the dissipated energy during the contact of the friction test. Then tribological behavior of 304 L stainless steel sliding against olive wood was studied. The steel was sensitive to tribo-oxidation, mostly due to abrasion by wood which presents a similar material to olive seed. © 2017 AFM, EDP Sciences.

Bouaziz F.,University of Sfax | Koubaa M.,CNRS Integrated Transformations of Renewable Matter | Barba F.J.,University of Valencia | Roohinejad S.,Shiraz University of Medical Sciences | Chaabouni S.E.,University of Sfax
Antioxidants | Year: 2016

Soluble flaxseed gum (SFG) was extracted from flax (Linum usitatissimum) hulls using hot water, and its functional groups and antioxidant properties were investigated using infrared spectroscopy and different antioxidant assays (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2' -azino-bis(3-ethylbenz othiazoline-6-sulphonic acid (ABTS), reducing power capacity, and β-carotene bleaching inhibition assay), respectively. The antioxidant capacity of SFG showed interesting DPPH radical-scavenging capacity (IC50 SFG = 2.5 mg.mL-1), strong ABTS radical scavenging activity (% inhibition ABTS = 75.6% + 2.6% at 40 mg.mL-1), high reducing power capacity (RPSFG = 5 mg.mL_1), and potent β-carotene bleaching inhibition activity (IC50 SFG = 10 mg.mL-1). All of the obtained results demonstrate the promising potential use of SFG in numerous industrial applications, and a way to valorize flaxseed hulls © 2016 by the authors; licensee MDPI, Basel, Switzerland.

Mansouri A.,University of Sfax | Bouhlel M.S.,University of Sfax
FTC 2016 - Proceedings of Future Technologies Conference | Year: 2016

A coloring of a graph is an assignment of colors to its nodes so that no two adjacent nodes are assigned the same color. Given a graph G, by a Grundy k-coloring of G mean any proper k-vertex coloring of G such that for each two colors i and j, i< j, every vertex of G colored by j has a neighbor with color i. The maximum k for which there exists a Grundy k-coloring is denoted by Γ (G) and called Grundy (chromatic) number of G. In this paper the authors introduce Grundy colorings and the authors give two algorithms to maintain the Grundy coloring of any graph G when a changement has been occurred (an edge is added or broken). © 2016 IEEE.

Kchaou M.,University of Sfax | Mat Lazim A.R.,University of Technology Malaysia | Abdul Hamid M.K.,University of Technology Malaysia | Abu Bakar A.R.,University of Technology Malaysia
Tribology International | Year: 2017

The disc brake squeal is a very annoying sound which affects the customer comfort. The generation of this noise is considered as a structural dynamics and/or tribological problems of the pad-disc system. Unlike drum brake design, this system is exposed to external environmental sand particles, wear debris and water spray. Their presence into the disc and pad interface may create dynamic and physics phenomena induced by friction surface changes which lead to brake noise and vibration issues. Thus, this paper aims to investigate the effect of environmental sand particles (silica sand and road sand particles) with a range size of 100–150, 150–200 and 300–400 µm on the brake squeal noise occurrences. The sensitivity of the sand particles to produce noise is correlated with the wear scar, friction coefficient and variation of brake operational parameters. It was concluded that the primary reason for the reduced squeal noise generation was contributed to the reduced COF with the particle embedment. The analysis of the particle size influence on the squeal occurrence indicated that a small size of silica sand particle produces less squeal occurrence than that of road sand particles. However, the biggest silica and sand particles seriously damage the pad surface and reduce consequently the real contact surface, inducing a decrease on the friction coefficient. © 2017 Elsevier Ltd

Hamed I.,University of Sfax | Ghozzi F.,University of Sfax
SIIE 2015 - 6th International Conference on "Information Systems and Economic Intelligence" | Year: 2015

ETL processes (Standing for Extract, Transform and Load) are focal component in the data warehousing projects. They supply the warehouse with the necessary integrated and reconciled data. However, they are the first to blame when wrong business decisions are made, as they provide incorrect or misleading data. Therefore a correct design of this process at early stages of data warehouse (DW) project is required. This calls for a specific knowledge to design ETL process able to provide data of good quality. A way to achieve this is to provide the ETL worker (designer, monitor, developer) with the necessary knowledge. Accordingly, we propose to anticipate the most likely to happen exceptions during ETL process and then to resolve it. Consequently, we provide a set of best practices and methodologies modeled as knowledge to the benefit of the ETL worker during the process lifecycle. Finally, we instantiate a prototype as an initial validation of this approach. © 2015 IEEE.

Salmouna A.,University of Sfax | Cojan I.,MINES ParisTech | Touir J.,University of Sfax
Journal of African Earth Sciences | Year: 2017

On the southern margin of the Tethys, Early Cretaceous sediments cover most of the Central Tunisia. As a result of a Middle Cretaceous sub-aerial exposure, the Late Barremian -Early Albian interval is mainly characterized by a major stratigraphic gap (hiatus). However in the Sidi Bouzid area a continental succession has been deposited called “Kebar Formation”. The Kebar Formation was previously studied in Jebel Kebar and Jebel Koumine and attributed respectively to the Late Aptian-Early Albian and the Late Barremian- Early Albian intervals. In the Jebel Ksaïra area, located at the East of Sidi Bouzid area and 4 km East of the Jebel Kebar, the Kebar Formation includes a rich association of charophytes that allows us to assign this Formation to the Late Barremian -Early Albian. Therefore, the Kebar Formation should have been deposited in Jebel Ksaïra earlier than in Jebel Kebar. The vertical stacking pattern and facies association of the Kebar Formation in the Jebel Ksaïra locality reflect variable depositional settings ranging from palustrine to marginal marine and infratidal environments. In fact, the sedimentary deposition in Jebel Ksaïra area was cyclic, alternating between (i) continental deposition materialized by bedded limestones rich in charophytes and limnic ostracods and (ii) marginal marine to infratidal deposition receiving episodically conglomerate inputs related to recurrent halokinetic activity (diapir of Jebel Rheouis). © 2017 Elsevier Ltd

Ben Ayed M.,University of Sfax | El Aoud N.,University of Sfax
International Journal of Healthcare Management | Year: 2017

The objective of this paper is to demonstrate that the patient empowerment, a concept that guaranties an effective self-management that improves health and well-being of sick individuals, adequately responds to the theoretical and practical requirements of healthcare marketing especially in its contribution to the voluntary health behavioral change. A discussion on the prospects offered by patient empowerment in healthcare marketing is tackled. Finally, limitations related to this concept should be emphasized that lead to new research horizons. © 2016 Informa UK Limited, trading as Taylor & Francis Group.

Mhamdi A.,University of Sfax | Naanaa W.,University of Sfax
Proceedings - 2016 IEEE 28th International Conference on Tools with Artificial Intelligence, ICTAI 2016 | Year: 2016

We consider the following vertex-partition problem on graphs: given a simple graph G = (V,E), we want to partition G into a disjoint union of cliques by only removing a minimum number of edges. This NP-hard optimization problem is referred to as the Cluster Deletion (CD). In this paper, we propose an encoding of CD in terms of a Weighted Constraint Satisfaction Problem (WCSP), a framework which has been widely used in solving hard combinatorial problems. We compare our approach with a fixed-parameter tractability algorithm, one of the most used algorithms for solving cluster deletion. Then, we experimentally show that significant results are obtained using the WCSP encoding. We compare both solution quality and running times of these algorithms on random graphs and protein similarity graphs derived from the COG dataset. © 2016 IEEE.

Frigui I.,University of Sfax | Karoui M.S.,University of Sfax | Ghariani H.,University of Sfax
International Design and Test Workshop | Year: 2017

The goal of this communication is to present a comparison between three dipole folded passive ultra-high frequency (UHF) tag antennas: a common dipole meander and two others with respectively square and triangular additional bends. The results demonstrate that the modified tag structures are a good alternative for a significant size reduction and they ensure dual-band antenna functionality as well. All designed tag antennas maintain the radiation patterns characteristics of the dipole antenna but they have different impacts on reflection coefficient, bandwidth and gain. Ultimately, the preferred structure is the most appropriate for the application. © 2016 IEEE.

Mzid R.,University of Sfax | Mzid R.,Tunis el Manar University | Abid M.,University of Sfax
International Design and Test Workshop | Year: 2017

Model-based approaches for the development of software intensive real-time embedded systems allow early verification of timing properties at the design phase. In order to perform such verification, some aspects of the target software platform (i.e. the Real-Time Operating System (RTOS)) need to be considered such as priorities, scheduling policies, etc. However, one of the basic principles of model-based approaches, is to keep RTOS-independence of the design model. Hence, some assumptions on the software platform are implicitly made to achieve timing verification. This approach may lead to a mismatch between the design model and the RTOS-specific model describing the real-time application and thus, at the implementation level, timing properties may be affected. To tackle this issue, we define in this paper a reconfigurable middleware called RT-Mw. This middleware aims to explicitly describe the software assumptions at the design level for timing verification. Such approach allows early verification of these assumptions before the effective deployment which may prevents the mismatch between the design and the RTOS-Specific models. RT-Mw is described using UML modeling language together with the MARTE Standard. © 2016 IEEE.

Yaich H.,University of Sfax | Masmoudi M.,University of Sfax
International Design and Test Workshop | Year: 2017

This article presents a new coders / decoders of images inspired by the retina for wireless sensors networks (WSN). Indeed, the problem of the compression is important for questions of energy saving, in particular for embedded system. We are convinced that a change is necessary in the philosophy which underlies the conception (design) of the coders / decoders of images to end in innovative and successful systems. The main hypothesis in this work is that the retina generates for the visual stimuli a compressed neural code. Our compression scheme is a combination of a compressed neural code of the retina and data compression techniques. © 2016 IEEE.

Daoud M.,University of Sfax | Mnif H.,University of Sfax | Ghorbel M.,University of Sfax
International Design and Test Workshop | Year: 2017

This paper presents the design and simulation results of a low power low noise amplifier (LNA) for 2.45 GHz industrial, scientific and medical (ISM) receiver for Body Area Network (BAN) in 0.18 um CMOS technology. This architecture is based on the resistive termination LNA. The proposed LNA consumes just 2.4 mW power. Its bandwidth is between 2 and 2.7 GHz. The simulated LNA shows a high voltage gain of about 22.7 dB with 0.86 dB minimal noise figure at 2.45 GHz frequency. It is characterized by an excellent input impedance equal to 48ω at 2.45GHz. © 2016 IEEE.

Daoud M.,National School of Technology | Mnif H.,National School of Technology | Ghorbel M.,University of Sfax
International Design and Test Workshop | Year: 2017

A resistive termination low noise amplifier (RTLNA) for biosensor application is presented. The proposed RTLNA consists of merging the block of the input impedance matching with the amplification block to reduce the LNA size. Several techniques are used to reach this goal. The exploitation of the internal capacitors of the CMOS transistors helped us to avoid the use of capacitors. The choice of the resistive termination LNA is explained by the good performances that offers this architecture like high gain, good linearity and stability. The RTLNA comprising only one inductor, resistor and four CMOS transistors without affecting the circuit performances. In the ISM band (2.45GHz) the proposed LNA achieves a maximum voltage gain of about 19.6 dB, a minimum noise figure of 4.8dB and an IIP3 of +4dBm. © 2016 IEEE.

Dakhli A.,Gabes University | Bellil W.,University of Sfax | Amar C.B.,University of Sfax
Advances in Intelligent Systems and Computing | Year: 2017

In this paper, we present a new method to cluster DNA sequence. The proposed method is based on using the Power Spectrum and the Wavelet Neural Network (WNN). The satisfying performance of the Wavelet Neural Networks (WNN) depends on an appropriate determination of the WNN structure. Our approach uses the Least Trimmed Square (LTS) to select the wavelet candidates from the Multi Library of the Wavelet Neural Networks (MLWNN) for constructing the WNN. The LTS has been able to optimize the wavelet neural network. The LTS algorithm is to find the regressors, which provide the most significant contribution to the approximation of error reduction. This wavelet can reduce the approximation error. In this study, the DNA sequence is coded by using a binary format. The Fourier transform is applied to attain respective Power Spectra (PS) by using the binary indicator sequence. The PS is applied to construct the mathematical moments which be used to build the vectors of real numbers, which are applied to compare easily the sequences with different lengths. Our aim is to construct classifier method that gives highly accurate results. This classifier permits to classify the DNA sequence of organisms. The classification results are compared to other classifiers. The experimental results have shown that the WNN-PS model outperformed the other classifier in terms of both the running time and clustering. In this paper, our approach consists of three phases. The first one, which is called transformation, is composed of three sub steps; binary codification of DNA sequences, Fourier Transform and Power Spectrum Signal Processing. The second section is the approximation; it is empowered by the use of Multi Library Wavelet Neural Networks (MLWNN). Finally, the third section, which is called the classification of the DNA sequences. The Euclidean distances is used to classify the signatures of the DNA sequences. © Springer International Publishing AG 2017.

Lazzez O.,University of Sfax | Ouarda W.,University of Sfax | Alimi A.M.,University of Sfax
Advances in Intelligent Systems and Computing | Year: 2017

In a relatively short period of time, we have observed the explosion of social network platforms which have acquired a prominent role in the people’s daily life. Hence, the extensive use of social networks has generated huge amounts of both visual and textual data that started to gain greater attention. However, the development of effective techniques for the acquisition and analysis of social data has drawn the attention of many researchers. The result of the huge mass of social data from different sources and types has provided many opportunities for researchers in the fields of discovering hidden soft biometrics information from data, which can be used for a variety of applications. In this paper, we propose a novel framework to understand and manage both textual and visual data form social networks, such as Facebook to extract the user’ soft biometrics information from posted pictures, specifically age, gender, race and smile. © Springer International Publishing AG 2017.

Chiha R.,University of Sfax | Ayed M.B.,University of Sfax
Advances in Intelligent Systems and Computing | Year: 2017

Recently, social networks have attracted a particular interest in the web, particularly Facebook. Consequently, a large amount of social data is produced. For semantic modeling of such data, several social network ontologies are introduced. The most popular is FoaF (Friend of a Friend) ontology. In our research, we are interested in data generated from Facebook social network. Heretofore, the semantic-temporal modeling of Facebook data is not yet studied. Thus, we propose a semantic modeling approach of social data that allows extending the FoaF ontology with Facebook data and temporal information. © Springer International Publishing AG 2017.

Akid H.,University of Sfax | Ayed M.B.,University of Sfax
Advances in Intelligent Systems and Computing | Year: 2017

Big Data generated from social networking sites is the crude oil of this century. Data warehousing and analysing social actions and interactions can help corporations to capture opinions, suggest friends, recommend products and services and make intelligent decisions that improve customer loyalty. However, traditional data warehouses built on relational databases are unable to handle this massive amount of data. As an alternative, NoSQL (Not only Structured Query Language) databases are gaining popularity when building Big Data Warehouses. The current state of the art of proposed NoSQL data warehouses is captured and discussed in this paper. The paper will also focus on the opportunities and challenges of using NoSQL graph databases for storing and querying Big Social Data and how graph theory can help to mine information from these data warehouses. © Springer International Publishing AG 2017.

Nacer H.,Gabes University | Mazouzi M.,University of Sfax
Advances in Intelligent Systems and Computing | Year: 2017

Vehicular Ad hoc NETwork (VANET) was proposed in order to prevent accidents and to improve road safety. Indeed, IEEE 1609.4 was developed to support multi-channel mechanism to provide both safety and non-safety applications. The CCH interval is also a key parameter for the 802.11p MAC protocol. In order to get a wide view of the different techniques used to broadcast a message, we evaluate the performance of the 802.11p MAC protocol with various vehicle densities and different CCH interval settings. Moreover, we propose SABM, a Scheduling Algorithm for vehicles attempting to transmit a Beacon Message, which firstly adjusts the CCH interval according to the road traffic and then schedule the safety messages based their priorities. The simulation results show that SABM outperforms the IEEE 802.11p MAC protocol. On one hand, we can significantly reduce the delivery delay and the collision probability, on the other hand, at the same time equilibrating the channel utilization ratio during CCH interval. © Springer International Publishing AG 2017.

Khrouf O.,University of Sfax | Khrouf K.,University of Sfax | Feki J.,University of Jeddah
Advances in Intelligent Systems and Computing | Year: 2017

OLAP (On-Line Analytical Processing) systems provide decision makers with multidimensional analyses of large databases by generating an aggregated vision of data. Nowadays, these systems face growing non-numeric data. In this context, we propose in this paper a new generic multidimensional model called CobWeb dedicated to the OLAP of XML documents; it is based on the concept of facet. The CobWeb model aims to ease the expression of queries; also it offers an appropriate vision of the document warehouse. In this context and for manipulation purposes, we propose new visualization operators for OLAP query results by using the concept of Tag clouds as a means to help decision-makers to see the content in an efficient manner and then to focus on the knowledge in results. © Springer International Publishing AG 2017.

Zouari R.,University of Sfax | Boubaker H.,University of Sfax | Kherallah M.,University of Sfax
Advances in Intelligent Systems and Computing | Year: 2017

This paper deals with a new system of online Arabic handwriting recognition based on the association of beta-elliptic modeling extractor with a hybrid Time Delay Neural Network (TDNN) and Support Vector Machines (SVM) classifier. The beta-elliptic model proceeds by a segmentation of the handwriting trajectory into fragments called Beta strokes by inspecting the extremums points of the curvilinear velocity and extracting their corresponding static and dynamic profile proprieties. These features are used to train the Time Delay Neural Network which is able to represent the sequential aspect of the input data. The fuzzy outputs of this network are then used to train SVM in order to predict the correct label class. To evaluate our method, we have used a total of 25000 Arabic letters from the LMCA database. Experimental results demonstrate the effectiveness of our proposed method and show recognition rate reaching the 99.52%. © Springer International Publishing AG 2017.

Ben Hassen M.,University of Sfax | Turki M.,University of Sfax | Gargouri F.,University of Sfax
Advances in Intelligent Systems and Computing | Year: 2017

Knowledge development in organizations relies on Sensitive Business Processes (SBPs), which are characterized by a high complexity and dynamism in their execution, high number of critical activities with intensive acquisition, sharing, storage and (re)use of very specific crucial knowledge, diversity of knowledge sources, and high degree of collaboration among experts. In this paper, we propose a semantically rich conceptualization for describing a SBP organized in a new Business Process Meta-model for Knowledge Identification (BPM4KI), in order to develop a rich and expressive graphical representation of SBPs to identify and localize the crucial knowledge. BPM4KI covers all aspects of business process modeling: the functional, organizational, behavioral, informational, intentional and knowledge perspectives. We focus more specifically on Knowledge Perspective which has not yet evolved into BP models. This perspective is semantically rich and well founded is on the «core» domain ontologies. Besides, we evaluate the relevance of some proposed concepts through a real SBP scenario from medical domain in the context of the organization of protection of the motor disabled people of Sfax-Tunisia. © Springer International Publishing AG 2017.

Zouari R.,University of Sfax | Boubaker H.,University of Sfax | Kherallah M.,University of Sfax
Advances in Intelligent Systems and Computing | Year: 2017

Handwriting recognition is an interesting part in pattern recognition field. In the last decade, several approaches are focused on online handwriting recognition because the very rapid growth of new technologies in the field of data entry. In this paper, we propose a new system for online Arabic handwriting recognition based on beta-elliptic model which allow to segment the trajectory into segments called strokes by inspecting the extremums points of velocity profile and extract their dynamic and geometric profiles. These strokes are used to train the Time Delay Neural Network (TDNN) which is able to represent the sequential aspect of input data. To evaluate our method, we have used a total of 25000 Arabic letters from the LMCA database. Our experimental results demonstrate the effectiveness of our proposed method and show recognition rates exceeds the 95%. © Springer International Publishing AG 2017.

Abbes H.,University of Sfax | Gargouri F.,University of Sfax
Advances in Intelligent Systems and Computing | Year: 2017

Ontologies provide shared and reusable pieces of knowledge about a specific domain. Building an ontology by hand is a very hard and prone to errors task. Ontology learning from existing resources provides a good solution to this issue. Databases are widely used to store data. They were often considered as the most reliable sources for knowledge extraction. NOSQL databases are more and more used to store data. MongoDB database is emerging as the fastest growing NOSQL database in the world. It belongs to the document oriented databases variant. This paper proposes an approach to learn OWL ontology from data in MongoDB database and describes a tool implementing transformation rules. © Springer International Publishing AG 2017.

Boussada E.B.,University of Sfax | Ayed M.B.,University of Sfax | Alimi A.M.,University of Sfax
Advances in Intelligent Systems and Computing | Year: 2017

Computer analysis of electrocardiogram (ECG) data has proven to be an important method to detect cardiac arrhythmias, so that can be of great assistance to the experts in detecting cardiac abnormalities. In this study, we propose to develop a system to aid in the diagnosis of anomalies cardiac signals. This system is based on data fusion and architected by using the multi-agents system. Therefore, the proposed system helps doctors to quickly and precisely diagnose a heart disease by examining only the class of the ECG beats. In order to achieve the goal of real-time classification, the data used are divided into two datasets: the training set for the unsupervised learning of the classifier and the testing set for the real-time classification. This system is tested on a MIT-BIH arrhythmia database. © Springer International Publishing AG 2017.

Hadjkacem B.,University of Sfax | Ayedi W.,University of Sfax | Abid M.,University of Sfax
Advances in Intelligent Systems and Computing | Year: 2017

Multi-shot human re-identification is a major challenge because of the large variations in a human’s appearance caused by different types of noise such as occlusion, viewpoint and illumination variations. In this paper, we presented a novel Gabor-LBP based video covariance descriptor, called GL-VC descriptor, which considers image sequences to extract appearance features, captures moving regions of interest and find the correlation between video frames. Therefore, it implicitly encodes the described human motion by the integration of temporal information and decreases the effect of occlusion. To deal with the changes of view points and illumination, the Local binary pattern (LBP) operators and Gabor bank were integrated into the spatio-temporal covariance features. We evaluated our GL-VC approach on the publicly available CAVIAR4REID multi-shot dataset and demonstrated superior performance in comparison with the current state-of-the-art. © Springer International Publishing AG 2017.

Boujelben A.,British Petroleum | Chaari T.,University of Sfax | Amous I.,British Petroleum
Advances in Intelligent Systems and Computing | Year: 2017

Information systems knowledge bases often include inference rules. The continuous growth of the facts in the recent information systems environments has caused the exponential increase of rule bases sizes. Therefore, rule bases management becomes more and more difficult. Such a task should be automated and based on the extraction of dependencies between rules in order to have a better insight on their correct execution order and to detect conflicts between them. In this paper, we describe a rules dependency extraction approach for Semantic Web Rule Language (SWRL) rules. Our approach insures the automatic extraction of a rule dependency graph based on the semantics of their components. We evaluated our work by applying it to two different ontologies from medical and network security domains. We have implemented a prototype of our approach and we integrated it in a plug-in for Potégé-Owl editor. © Springer International Publishing AG 2017.

Mezghanni I.B.,University of Sfax | Gargouri F.,University of Sfax
Journal of King Saud University - Computer and Information Sciences | Year: 2017

Legal ontologies have proved their increasingly substantial role in representing, processing and retrieving legal information. By using the knowledge modeled by such ontologies in form of concepts and relations, it is possible to reason over the semantic content of legal documents. Supporting (semi-) automatically the development of ontologies from text is commonly referred to as ontology learning from text. The learning process includes learning of the concepts that will form the ontology and learning of the semantic relations among them.In this paper, we present a new approach for expliciting the semantic relations between Arabic compound nouns concepts. The originality of this work is twofold. Firstly, the technique of inferring relations is based on exploiting the internal structure of the compounds using a defined set of domain-and language-independent rules according to their different structures, on the one hand, and on studying prepositions semantics specifying the inferred relations applying a gamification mechanism that collects human votes, on the other hand. Secondly, relying on the compounds set described by both binary (structural positions in which there are written) and relational attributes (the deduced relations), we used a "Relational Concept Analysis" (RCA) technique, as an adaptation of "Formal Concept Analysis" (FCA), for the construction of interconnected lattices that we transformed into ontological concepts and relations which can be either taxonomic or transversal.Experiments carried out on Arabic legal dataset showed that the proposed approach reached encouraging performance through achieving high precision and recall scores. This performance affects positively the retrieval results of legal documents based on a powerful ontology, which presents our main objective. © 2017 The Authors.

Othmani C.,University of Sfax | Takali F.,University of Sfax | Njeh A.,University of Sfax
Superlattices and Microstructures | Year: 2017

In this paper, the propagation of the Lamb waves in the GaAs-FGPM-AlAs sandwich plate is studied. Based on the orthogonal function, Legendre polynomial series expansion is applied along the thickness direction to obtain the Lamb dispersion curves. The convergence and accuracy of this polynomial method are discussed. In addition, the influences of the volume fraction p and thickness hFGPM of the FGPM middle layer on the Lamb dispersion curves are developed. The numerical results also show differences between the characteristics of Lamb dispersion curves in the sandwich plate for various gradient coefficients of the FGPM middle layer. In fact, if the volume fraction p increases the phase velocity will increases and the number of modes will decreases at a given frequency range. All the developments performed in this paper were implemented in Matlab software. The corresponding results presented in this work may have important applications in several industry areas and developing novel acoustic devices such as sensors, electromechanical transducers, actuators and filters. © 2017 Elsevier Ltd

Ghodhbani A.,University of Sfax | Haj Taieb E.,University of Sfax
International Journal of Pressure Vessels and Piping | Year: 2017

Friction coupling affects water hammer evolution in pipelines according to the initial flow regime. Unsteady friction models are only validated with uncoupled formulation. On the other hand, coupled models such as four-equation model, provide more accurate prediction of water hammer since fluid-structure interaction (FSI) is taken into account, but they are limited to steady-state friction formulation. This paper deals with the creation of the “four-equation friction model” which is based on the incorporation of the unsteady head loss given by an unsteady friction model into the four-equation model. For transient laminar flow cases, the Zielke model is considered. The proposed model is applied to a quasi-rigid pipe with axial moving valve, and then calculated by the method of characteristics (MOC). Damping and shape of the numerical solution are in good agreement with experimental data. Thus, the proposed model can be incorporated into a new computer code. © 2017 Elsevier Ltd

Malem D.,Hollywood Hospital | Bangash H.K.,Royal Perth Hospital | Mwipatayi B.P.,University of Sfax
Annals of Vascular Surgery | Year: 2017

Primary axillary venous aneurysms (VAs) are rare, and there are only a handful of cases reported previously. The patient can be either asymptomatic or symptomatic and can present with local axillary swelling, dilated venules in overlying skin associated with local discomfort, peripheral neuropathy, or pulmonary embolisms. A 30-year-old man presented with a 4-month history of an uncomfortable lump in his left armpit that was associated with paresthesia radiating down to his left forearm and hand. He had no history of arm swelling and had a normal motor neurological examination. The clinical examination revealed a nontender palpable mass within the left axilla. Venous duplex imaging confirmed the diagnosis of axillary vein aneurysm measuring 6.1 cm. He underwent elective aneurysmorrhaphy repair of the axillary/basilic VA with satisfactory outcome. We present a rare case of a symptomatic primary axillary VA that was managed surgically with complete resolution of symptoms. © 2017 Elsevier Inc.

Mokni R.,University of Sfax | Kherallah M.,University of Sfax
2016 IEEE International Conference on Systems, Man, and Cybernetics, SMC 2016 - Conference Proceedings | Year: 2016

This paper presents a new method to recognize the person's identity through their palmprints. Palmprint recognition is among the most reliable physiological characteristics that can be used especially in forensic applications thanks to its simplicity and its ease of use, its user friendliness and high identification reliability. Accordingly, it has gained great popularity within the pattern recognition field over the past three decades. In this paper, we suggest a new approach for personal identification based on palmprint features extracted using the various methods of fractal theory. These methods have been broadly applied in image processing fields to estimate the fractal dimensions of an image as an important parameter for the analysis of objects of irregular shapes of the texture image. The novelty of this approach is two-fold. On the one hand, we apply the Box counting (BC), the Mass Radius (MS) and the Cumulative Intersection (CumInt) methods to extract the palmprint texture information. On the other hand, the combination of efficient information from the three descriptors has been presented in order to make identification system more efficient and achieve better performances. Then, we explore such texture information features by using classical machine learning techniques: the K-Nearest Neighbor (KNN), the Support Vector Machine (SVM) and the Multiclass Random Forest classification algorithms. The results of the experiments conducted on two large datasets show that our proposed method gives better recognition rates of about 96.35% for CASIA-Palmprint dataset and 95.98% for IITD-Touchless-Palmprint dataset. These results obtained are compared to other well-known state-of-the-art approaches. © 2016 IEEE.

Said F.B.,University of Sfax | Alimi A.M.,University of Sfax
2016 IEEE International Conference on Systems, Man, and Cybernetics, SMC 2016 - Conference Proceedings | Year: 2016

Online Feature Selection (OFS) is an important technique in pattern recognition and machine learning. Our challenge is how to enhance the classification performance in real contexts where the large-scale training data arrive sequentially with a big number of features. The major problem is how to choose the best accurate and efficient state-of-The art OFS method that can select the relevant features or if we do a combination between these methods can we improve the classification performance? In this paper, we propose a framework of OFS using the characteristics of multi-agent systems (MAS) to overcome this challenge. We propose firstly a new OFS model; Agent-Learner based OFS (ALOFS) which represents each agent in our MAS. ALOFS is a generalization of first-order and second-order online learning methods based feature selection. Secondly, we propose the Multi Agent-Learner based OFS (MALOFS) system which is our MAS. MALOFS uses two levels of selection: the first level aims to select the more confident learners and the second level has as object to select the relevant features using a proposed negotiation method (MANOFS). MALOFS is applicable to different domains successfully and achieves highly accuracy with some real world applications. © 2016 IEEE.

Zahmoul R.,University of Sfax | Zaied M.,University of Sfax
2016 IEEE International Conference on Systems, Man, and Cybernetics, SMC 2016 - Conference Proceedings | Year: 2016

Recent research on image encryption algorithms has been increasingly based on chaotic systems, but the drawbacks of small key space and weak security in chaotic cryptosystems are obvious. In this paper, new chaotic maps based on beta function were created. The generation of different pseudo random sequences was carried out to shuffle the position of the image pixels and to confuse the relationship between the encrypted image and the original image, thereby significantly increasing the resistance to attacks. The proposed system has the advantage of high security analysis such as key space, statistical and sensitivity analysis. © 2016 IEEE.

Dammak M.,University of Sfax | Amar C.B.,University of Sfax
2016 IEEE International Conference on Systems, Man, and Cybernetics, SMC 2016 - Conference Proceedings | Year: 2016

A novel proposed approach, collaborative representation-based classification, has been developed for face recognition and recently used in image classification task owing to its simplicity and effectiveness. The major drawback of this method is the neglect of the spatial structure among the image representations. Inspired by the success of this technique and motivated by the power of spatial information in improving the image representation, we suggest in this paper a novel collaborative approach named spatial collaborative representation based classification. After applying the feature encoding and the pooling method, we exploit the global manifold structure of the image by applying the spatial pyramid representation. After that, two successive steps are required in order to obtain the label category for each image. In the first step we apply the standard collaborative method for each histogram generated at each pyramid level. The second stage aims to combine efficiently the image reconstruction results in order to predict the category label. © 2016 IEEE.

Chaabouni O.,University of Sfax | Boufi S.,University of Sfax
Carbohydrate Polymers | Year: 2017

Cellulose nanofibrils (CNFs) are nanoscale cellulose produced from renewable resources with strong reinforcing potential when included in a polymer matrix. In this work, the effect of the addition of CNFs on the properties of waterborne polyvinylacetate (PVA) adhesive was investigated. Adhesive formulations with different contents in CNFs from 1 to 10 wt.% was prepared by simple mixing of PVA dispersion with CNFs suspension in water. The viscosity of the adhesive increased with the addition of CNFs, namely over a content of 5%. Shear strength of wood joints at dry as well as wet conditions was improved by CNFs inclusion. Adding 10% of CNF to the PVA adhesive increased the shear strength by about 2 folds compared to the neat adhesive. This strengthening effect was explained by the strong reinforcing impact brought by CNFs inclusion in the PVA matrix. The addition of CNFs also improved the water resistance of PVA adhesive and strongly enhanced the mechanical performance in wet conditions, namely over 7% of CNF content. © 2016 Elsevier Ltd

Laajimi R.,University of Sfax
2013 International Conference on Control, Decision and Information Technologies, CoDIT 2013 | Year: 2013

Operational transconductance amplifier (OTA) is one of the most significant building-blocks of analog Very Large Scale Integration (VLSI). For high-performance analog circuit applications, the bandwidth and power consumption are the most important parameters to determine the performance of the OTA. In this paper a comparison of two architectures OTA based on the same topology is presented. Simulation results are shown for low power OTA and wide bandwidth OTA. The gain is 58 dB and 60 dB, slew rate is 7.7 V/μs and 70 V/μs, Cut-off frequency is 20 KHz and 250 KHz, settling time is 32 ns and 15 ns at ±1.5V supply voltage. Eventually we have succeeded in reducing the static power consumption to 0.036 mW for first version of OTA, and increase a Gain bandwidth to 126 MHz for second version of OTA. © 2013 IEEE.

Benkhalifa J.,University of Sfax | Chaabane M.,University of Sfax
Journal of Atmospheric and Solar-Terrestrial Physics | Year: 2016

The atmosphere contains molecules, clouds and aerosols that are sub-millimeter particles having a large variability in size, shape, chemical composition, lifetime and contents. The aerosols concentration depends greatly on the geographical situation, meteorological and environmental conditions, which makes aerosol climatology difficult to assess. Setting up a solar photometer (automatic, autonomous and portable instrument) on a given site allows carrying out the necessary measurements for aerosol characterization. The particle microphysical and optical properties are obtained from photometric measurements. The objective of this study is to analyze the spatial variability of aerosol optical thickness (AOT) in several Mediterranean regions and Central Africa, we considered a set of simultaneous data in the AErosol RObotic NETwork (AERONET) from six sites, two of which are located in Central Africa (Banizoumbou and Zinder Airport) and the rest are Mediterranean sites (Barcelona, Malaga, Lampedusa, and Forth Crete). The results have shown that the physical properties of aerosols are closely linked to the climate nature of the studied site. The optical thickness, single scattering albedo and aerosols size distribution can be due to the aging of the dust aerosol as they are transported over the Mediterranean basin. © 2016 Elsevier Ltd.

Moussa A.B.,University of Sfax | Zouari K.,University of Sfax | Marc V.,Laboratoires dHydrogeologie dAvignon
Physics and Chemistry of the Earth | Year: 2011

Major elements concentration, stable (δ18O,δ2H) and radiogenic (3H,14C) isotopes are known to provide important additional information to more traditional hydrological data and unravel the processes that underpin the large variations in chemical composition within the Hammamet-Nabeul shallow aquifer, north-eastern Tunisia (Cap Bon peninsula). The hydrogeochemical investigations of Hammamet-Nabeul shallow aquifer show that groundwaters can be classified into two major water facies: Ca-SO4-Cl and Na-Cl. The main hydrogeochemical processes that typically control the groundwater mineralization are dissolution of evaporates (halite, gypsum and anhydrite), cation exchange and mixing processes related to the return flow of irrigation waters. The stable isotope signatures reveal that the main part of groundwater are not significantly affected by evaporation, which give evidence of a recharge mostly from the foot hill zone in the north of the basin. The tritium and carbon-14 data show mixing processes between modern and old water and suggest that groundwaters recharge occurs according to a long flow path. Nevertheless, moderated evaporation of waters was observed in the southern part of the basin, especially in the agricultural areas. © 2010 Elsevier Ltd.

Daassi D.,University of Sfax | Rodriguez-Couto S.,Centro de estudios e investigaciones técnicas de Gipuzkoa | Rodriguez-Couto S.,Ikerbasque | Nasri M.,University of Sfax | Mechichi T.,University of Sfax
International Biodeterioration and Biodegradation | Year: 2014

Synthetic dyes are extensively used in a number of industries, such as textile dyeing. Due to their low biodegradability, they cause serious environmental pollution. Thus, in the present paper a partially-purified acid fungal laccase from the white-rot basidiomycete Coriolopsis gallica was entrapped into calcium alginate beads and applied to the decolorization of different synthetic dyes. Effects of immobilization conditions such as alginate concentration, CaCl2 concentration and the ratio enzyme/alginate (E/A) on the loading efficiency and immobilization yield were investigated. The optimal conditions for C.gallica laccase immobilization into Ca-alginate beads were 2% (w/v) sodium alginate, 2% (w/v) CaCl2, and 1:4E/A (v/v). It was also found that laccase stability to pH and temperature increased after immobilization.Both the free and immobilized laccase alone showed a high efficiency to decolorize the anthraquinone dye Remazol Brilliant Blue R (RBBR) while a low decolorization yield was observed for the diazo dyes Reactive Black 5 (RB5) and Bismark Brown R (BBR) and the metal textile dye Lanaset Grey G (LG). The addition of the redox mediator 1-hydroxybenzotriazole (HBT) to the decolorization reaction increased significantly dye removal. The immobilized laccase retained 70% of its activity after four successive decolorization cycles except for BBR (51.2%). The results obtained showed that the immobilized laccase from C.gallica has potential for its application in dyestuff treatment. © 2014 Elsevier Ltd.

Mnif S.,University of Sfax | Sayadi S.,University of Sfax | Chamkha M.,University of Sfax
International Biodeterioration and Biodegradation | Year: 2014

An aerobic, thermophilic, halotolerant, Gram-positive and sporulated bacterium, designated strain VP3, was isolated from a geothermal oil field, located in Sfax, Tunisia, after enrichment on vanillic acid. The temperature range for growth was 37-65°C, with optimal growth occurring at 55°C. The NaCl concentration range for growth was 0-80gl-1, with an optimum at 10gl-1 NaCl. Strain VP3 was able to degrade completely 5mM vanillic acid after 9h of incubation, at 55°C and in the presence of 30gl-1 NaCl. Strain VP3 was also found to degrade, under saline and thermophilic conditions, a wide range of other aromatic compounds, including benzoic, p-hydroxybenzoic, protocatechuic, p-hydroxyphenylacetic, cinnamic, p-coumaric, caffeic and ferulic acids, phenol and m-cresol. In addition, the bacterium was grown on crude oil and diesel as sole carbon and energy sources. Phenotypic characteristics and phylogenetic analysis of the 16S rRNA gene sequence of isolate VP3 revealed that it was very closely related to Aeribacillus pallidus, with sequence similarity of 99%. © 2013 Elsevier Ltd.

Anane S.,University of Sfax
Journal de Mycologie Medicale | Year: 2012

Introduction: Epidemiological investigation of keratinophilic fungi in soil has been carried out in different parts of the world. However, our knowledge of the present occurrence and distribution of keratinophilic fungi in Tunisian soils remains unknown. This study was carried out to evaluate the epidemiological characteristics of keratinophilic fungi in the soils collected in Djerba (South of Tunisia). Material and methods: One hundred and forty one soil samples were collected from various sites in Djerba and screened for the presence of keratinophilic fungi and related dermatophytes using hair-baiting technique. Fungi were identified using macro- and micro-morphological features. Results: Among them, 29 (20.6%) soil samples were positive. Seven species were isolated in the following order of dominance: Chrysosporium keratinophilum (48.3%), Microsporum gypseum (41.4%), C. tropicum (10.4%), C. parvum (3.45%), C. anamorph of Anixiopsis stercoraris (3.45%), C. anamorph of Arthroderma cuniculi (3.45%) and Chaetomium sp. (3.45%). The association of M. gypseum and C. keratinophilum was detected in 13.8% of positive soils. Sixty-nine percent of fungi were found in organic matter rich soil. Our results revealed a higher prevalence of keratinophilic fungi in the regions far from the sea (33.3%) than in those near the sea (11.1%) with a statistically significant difference (P=0.001). All keratinophilic fungi were isolated from soils with pH ranging from 6.2 to 7.6. Conclusion: Our study showed that keratinophilic fungi were present in the various soils of Djerba. They may represent a risk to human health. © 2012 Elsevier Masson SAS.

Boufi S.,University of Sfax | Vilar M.R.,University Paris Diderot | Ferraria A.M.,University of Lisbon | Botelho do Rego A.M.,University of Lisbon
Colloids and Surfaces A: Physicochemical and Engineering Aspects | Year: 2013

Silver and gold nanoparticles (NPs) were generated via a mild wet-chemistry process in aqueous chitosan solutions. Gold and silver NPs were created in situ in presence of chitosan through the addition of the corresponding salt solution under a subsequent UV irradiation. Gold and silver NPs were also created by using a sequence of gold and then silver and vice versa. The amine function existing in the chain monomer operates as the anchoring centre of the metal NP, enabling thus a selective generation of the metal NPs through their nucleation followed by their growth. Ensuing hybrid systems were characterized by UV/vis spectroscopy, X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy (TEM) and Grazing Incident X-ray Diffraction (GIXRD). The NPs average sizes ranges from 10 to 40. nm for gold and 20 to 100. nm for silver. XPS studies on NPs generation through a sequence of gold followed by silver solutions suggest that gold cores enveloped by silver shells with some discontinuities exist. © 2013 Elsevier B.V.

Ktari N.,University of Sfax | Ben Khaled H.,University of Sfax | Nasri R.,University of Sfax | Jellouli K.,University of Sfax | And 2 more authors.
Food Chemistry | Year: 2012

An alkaline trypsin was purified from the viscera of zebra blenny (Salaria basilisca) by ammonium sulphate (40-80% saturation) precipitation, Sephadex G-100, Mono Q-Sepharose and ultrafiltration. A yield of 12% with a purification-fold of 4.2 was obtained. The trypsin had an apparent molecular weight of 27 kDa. Soybean trypsin inhibitor and phenylmethylsulfonyl fluoride showed a strong inhibitory effect on the purified trypsin. Trypsin had maximal activity at pH 9.5 and 60 °C for the hydrolysis of Nα-benzoyl-dl- arginine-p-nitroanilide (BAPNA). It was stable at low temperatures and in the pH range of 7.0-12.0. The N-terminal amino acid sequence of the first 12 amino acids of the purified protease was IVGGRECTEPSQ. S. basilisca trypsin, which showed high homology with other fish trypsins, had a charged Arg residue at position 5, where Tyr is common in marine vertebrates and mammalian trypsins. The trypsin kinetic constants, Km and kcat for BAPNA, were 0.6 mM and 1.38 s-1, respectively. © 2011 Elsevier Ltd. All rights reserved.

Caldeira D.,University of Sfax | David C.,University of Sfax | David C.,University of Santa María in Ecuador | Sampaio C.,University of Sfax | Sampaio C.,Institute of Molecular Medicine
Journal of Hospital Infection | Year: 2011

Blood cultures drawn by venous puncture are common clinical procedures for the detection of bacteraemia. Blood culture contamination (BCC) can lead to clinical misinterpretation and unnecessary expenses. We aimed to systematically review randomised controlled trials (RCTs) with skin antiseptics for prevention of contamination in venous-puncture drawn blood cultures. We conducted database search using CENTRAL (Cochrane Library issue April 2010), MEDLINE, EMBASE and mRCT, in June 2010. All RCTs testing skin antiseptics in venous-puncture drawn blood cultures were retrieved. Relative risk (RR) of the BCC outcome was analysed by random effects method using confidence interval (CI) of 95%. Studies were assessed by one review author and checked by another. Six studies were identified. Single-trial comparisons showed that alcoholic iodine tincture was better than non-alcoholic povidone-iodine, and isopropyl/acetone/povidone-iodine showed superiority against isopropyl/povidone-iodine. Meta-analysis demonstrated that alcoholic chlorhexidine was better than non-alcoholic povidone-iodine (RR: 0.33; 95% CI: 0.24-0.46) in 4757 blood cultures from two trials. Alcoholic solutions were better than non-alcoholic products (0.53; 0.31-0.90) in 21 300 blood cultures from four studies. Two trials with 13 418 blood cultures showed that iodine tincture was not superior to povidone-iodine in BCC prevention (0.79; 0.54-1.18). Alcoholic iodine was not different from non-alcoholic iodine (0.79; 0.53-1.17). Comparison of chlorhexidine vs iodine compounds was not conclusive. Alcohol alone was not inferior to iodinated products for prevention of contamination in venous-puncture drawn blood cultures. The association of alcohol and povidone-iodine did not seem to be useful. Alcoholic chlorhexidine solutions reduced blood culture false positives compared with aqueous povidone-iodine. © 2010 The Hospital Infection Society.

Sghari M.B.A.,University of Sfax | Hammami S.,University of Sfax
Energy Reports | Year: 2016

Since the United Nations Conference on Environment and Development held its Rio meeting in 1992, where participants discussed the necessity of fighting against the hazardous effects of pollution and climate change, these issues have become even more pressing world-wide. The ever-increasing consumption of energy is depleting the planet's natural capital to a degree that could impact our future prosperity. According to the 2008 Living Planet Report, if demands for energy were to continue to grow at their current rates, by the mid-2030s we would need the equivalent of two planets to meet our global supply needs.1 The rising level of energy consumption that is occurring internationally also is being mirrored at regional and national levels. An interesting case study along these lines is Tunisia, which is one of the high-growth economies in the Middle East and North African area yet lacks sufficient energy supply to satisfy its growing demand. Tunisia looks like many nations around the world with a young population, growing economy, increasing domestic energy consumption, and the need to balance economic development with environmental concerns. © 2016 The Authors.

Ben Aouicha M.,University of Sfax | Hadj Taieb M.A.,University of Sfax
Journal of Biomedical Informatics | Year: 2016

The exploitation of heterogeneous clinical sources and healthcare records is fundamental in clinical and translational research. The determination of semantic similarity between word pairs is an important component of text understanding that enables the processing and structuring of textual resources. Some of these measures have been adapted to the biomedical field by incorporating domain information extracted from clinical data or from medical ontologies such as MeSH. This study focuses on Information Content (IC) based measures that exploit the topological parameters of the taxonomy to express the semantics of a concept. A new intrinsic IC computing method based on the taxonomical parameters of the ancestors' subgraph is then assigned to a biomedical concept into the "is a" hierarchy. Moreover, we present a study of the topological parameters through the MeSH taxonomy. This study treats the semantic interpretation and the different ways of expressing the parameters of depth and the descendants' subgraph. Using MeSH as an input ontology, the accuracy of our proposal is evaluated and compared against other IC-based measures according to several widely-used benchmarks of biomedical terms. The correlation between the results obtained for the evaluated measure using the proposed approach and those from the ratings of human' experts shows that our proposal outperforms the previous measures. © 2015 Elsevier Inc.

Kaabi F.,Laboratory MIRACL | Gargouri F.,University of Sfax
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016

This paper introduces an extensional and asymmetric alignment approach capable of identifying complex mappings between OWL ontologies. This approach employ the association rule to detect implicative and conjunctive mapping containing complex correspondences. Method for extracting the complex mappings is presented and results of experiments carried out on the large biomedical ontologies and the anatomy track available to Test library of Ontology Alignment Evaluation Initiative show the efficiency of the approach proposed. © Springer International Publishing Switzerland 2016.

Elleuch A.,University of Sfax | Yu J.,Tianjin University of Technology | Boussetta A.,University of Sfax | Halouani K.,University of Sfax | Li Y.,Tianjin University of Technology
International Journal of Hydrogen Energy | Year: 2013

As a promising intermediate temperature fuel cell, Direct Carbon Fuel Cell (DCFC) with composite electrolyte composed of Samarium-Doped Ceria (SDC) and a binary carbonate phase (67 mol% Li2CO3/33 mol% Na 2CO3) has a much higher efficiency compared with conventional power suppliers. In the present work, SDC powder has been synthesized by an oxalate co-precipitation process and used as solid support matrix for the composite electrolyte. Single cell with composite electrolyte layer is fabricated by a dry-pressing technique using LiNiO2/Li 2Na2CO3/SDC as cathode and 1:9 (weight ratio) graphite mixture with 67 mol% Li2CO3/33 mol% Na 2CO3 molten carbonate as anode. The cell is tested at 600-750 C using electrolytical graphite mixture as fuel and O 2/CO2 mixture as oxidant. A relatively good performance with high power density of 58 mW cm-2 at 700 C is achieved for a DCFC using 0.8 mm thick composite electrolyte layer. The sensibility of the 1 cm2 DCFC single cell performance to the anode gas nature is also investigated. At temperatures higher than 700 C, both carbon (C) and carbon monoxide (CO) can be considered as reacting fuel for the DCFC system. © Copyright © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Sahraoui M.,University of Carthage | Bichioui Y.,University of Carthage | Halouani K.,University of Sfax
International Journal of Hydrogen Energy | Year: 2013

A three dimensional two phase flow model is proposed to study transport phenomena in a PEMFC. In order to capture the effects of liquid water on the performance of the fuel cell, all regions are modeled from the anode to the cathode as having finite thickness. The geometry of the bipolar plate is modeled in detail to capture the effect of liquid water accumulation under the channel rib. This model takes into account the effect of temperature and inlet RH of both the anode and cathode. The three-dimensional model uses the finite volume method to solve the equations of mass conservation, momentum, energy, species transfer and protonic potential. These equations include the effect of liquid water on the transport properties as well as the electrochemical source. The effects of water on ohmic losses are presented for different humidity conditions of the anode and cathode at various fuel cell temperatures. © Copyright © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Stolic R.,University of Sfax
Medical Hypotheses | Year: 2010

The results of numerous investigations on the impact of obesity on renal insufficiency conducted in recent years introduce certain dilemmas about their mutual agreement. Some studies suggest that obesity is negatively correlated with the terminal phase of renal failure. On the other hand, other research has shown that reducing the index of body weight of patients with renal disease improves glomerular filtration. Even more confusion comes from findings indicating that metabolic syndrome in non-diabetic renal disease sufferers increases the risk of occurrence and progression of chronic renal disease.However, some research results suggest that obesity is positively correlated with survival of patients on dialysis, i.e., the higher the index of body weight the lower the mortality rate, especially with extremely obese patients. Reverse epidemiology is a term for the medical hypothesis which holds that the influence of obesity and high body weight indexes may be protective and associated with greater survival of obese patients on haemodialysis.A high serum creatinine concentration is a direct consequence of low rates of glomerular filtration and is inversely correlated with mortality rate. However, observations that high creatinine concentrations before haemodialysis treatment are a predictor of survival may be explained by the fact that they are also the direct consequence of increased muscle mass and a higher dietary protein intake. Thus, improvement of their nutritive state might delay progression and diminish the complications expected for patients suffering from kidney insufficiency. The requirements for daily protein intake by dialysis patients are not clear enough, while a hyperprotein diet may be a significant source of uraemic toxins, phosphate and H +-ion, which would be detrimental for their health.Some research has indicated that obesity of dialysis patients is not linked to increased risk of cardiovascular diseases in contrast to the general population. On the other hand, a low body mass index and additional parameters of malnutrition are strong independent indicators of mortality rate in dialysis patients.Although, there is a substantial amount of data that support a protective role for obesity, some authors question the existence of the obesity paradox. They do not oppose the results of that research, but suggest that obese individuals are actually protected in the short-term while later on they are liable to higher mortality risks than people of normal body weight.The role of obesity is undisputed as a significant mortality factor in the general population. Nevertheless, some well-designed studies have confirmed that obesity has a protective influence on patients treated by chronic dialysis procedures. This is not to suggest that obesity is recommended as a model for a higher survival rate in those patients, but the role of 'uraemic adipose tissue' and probable additional factors that might result in a lower mortality rate should be considered. © 2010 Elsevier Ltd.

Zekri F.,University of Sfax | Bouaziz R.,University of Sfax
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016

The explosion of medical knowledge and the uncertainty of some patient information in several diseases cause many clinical errors in medical decision support systems. Therefore, we aim to reduce these deficiencies using new decision support approach and new improvements. In this paper, we present a new way to manage rules in expert systems. First, we propose a knowledge specialization process that uses three types of rule bases. Then we explain how we can manage rules across these three types of rule bases. Finally, we present an implementation of a rule management system for the Alzheimer disease. We think that this improvement can enhance clinical decision support expert system performances to better support medical decision support. © Springer International Publishing AG 2016.

Zouari M.,University of Sfax | Kharrat M.,University of Sfax | Dammak M.,University of Sfax
Surface and Coatings Technology | Year: 2010

The friction and wear behaviors of polyester coatings incorporating graphite particles and deposited on an aluminum substrate by a spraying technique were analyzed in this study. Four volume ratios of the graphite particles in the polyester matrix were considered in the range of 0% to 35%. The coatings tribological behaviors were analyzed using high chromium steel ball antagonist. The friction experiments were conducted using a reciprocating tribometer. For each of the considered coating, evolutions of the friction coefficient, the weight losses and the wear scar morphology with the number of sliding cycles were analyzed. The microstructure of polyester coatings and the wear scar micrographs were characterized using an optical microscope and a scanning electron microscope (SEM). Severe wear mechanism is activated for the polyester coating without graphite particles. Incorporating graphite particles in the polyester coating enhances the development of a specific third body which reduces friction and wear. The best friction and wear properties are obtained for highest ratio were the third body was formed on the entire sliding stripe. © 2010 Elsevier B.V.

Mbarek R.,University of Sfax | Tmar M.,University of Sfax | Hattab H.,University of Umm Al - Qura
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2014

The idea of Relevance Feedback is to take the results that are initially returned from a given query and to use information about whether or not those results are relevant to perform a new query. The most commonly used Relevance Feedback methods aim to rewrite the user query. In the Vector Space Model, Relevance Feedback is usually undertaken by re-weighting the query terms without any modification in the vector space basis. With respect to the initial vector space basis(index terms), relevant and irrelevant documents share some terms (at least the terms of the query which selected these documents). In this paper we propose a new Relevance Feedback method based on vector space basis change without any modification on the query term weights. The aim of our method is to build a basis which optimally separates relevant and irrelevant documents. That is, this vector space basis gives a better representation of the documents such that the relevant documents are gathered and the irrelevant documents are kept away from the relevant ones. © 2014 Springer-Verlag Berlin Heidelberg.

Khacharem A.,University of Sfax | Khacharem A.,University of Valenciennes and Hainaut‑Cambresis
Journal of Sports Sciences | Year: 2016

Comprehension of a narrated diagram entail complex cognitive processing as learner is challenged to extract the orally evoked information. The present experiment examined the effects of 2 different forms of attention guidance – bottom-up and top-down – on comprehension performance, cognitive load investment, and motivation to learn, using a 2 × 2 mixed design with factors “Expertise” (Expert vs. Novice) and “Condition” (no-signal, circle, segment). The results revealed an expertise reversal effect indicating that the incorporation of visual signals in diagram is effective for novice learners but partially reverses and becomes ineffective for more experienced learners (even though they invested less mental effort and reported higher level of motivation in the segmented condition). The findings suggested that the effectiveness of instructional guidance depends heavily on levels of prior knowledge. © 2016 Informa UK Limited, trading as Taylor & Francis Group

Saidi K.,University of Sfax | Mbarek M.B.,University of Sfax
Environmental Science and Pollution Research | Year: 2016

This study attempts to empirically examine the impact of financial development, income, trade openness, and urbanization on carbon dioxide emissions for the panel of emerging economies using the time series data over the period 1990–2013. Results showed a positive monotonic relationship between income and CO2 emissions. All models do not support the EKC hypothesis which assumes an inverted U-shaped relationship between income and environmental degradation. Financial development has a long-run negative impact on carbon emissions, implying that financial development minimizes environmental degradation. This means that financial development can be used as an implement to keep the degradation environmental clean by introducing financial reforms. The urbanization decreases the CO2 emissions; therefore, it is important for the policymakers and urban planners in these countries to slow the rapid increase in urbanization. © 2016 Springer-Verlag Berlin Heidelberg

Younes I.,University of Sfax | Hajji S.,University of Sfax | Frachet V.,Joseph Fourier University | Rinaudo M.,Biomaterials Applications | And 2 more authors.
International Journal of Biological Macromolecules | Year: 2014

Chitin was recovered through enzymatic deproteinization of the shrimp processing by-products. Different microbial and fish viscera proteases were tested for their deproteinization efficiency. High levels of protein removal of about 77. ±. 3% and 78. ±. 2% were recorded using Bacillus mojavensis A21 and Balistes capriscus proteases, respectively, after 3. h of hydrolysis at 45. °C using an enzyme/substrate ratio of 20. U/mg. Therefore, these two crude proteases were used separately for chitin extraction and then chitosan preparation by N-deacetylation.Chitin and chitosan samples were then characterized by 13 Cross polarization magic angle spinning nuclear magnetic resonance (CP/MAS)-NMR spectroscopy and compared to samples prepared through chemical deproteinization. All chitins and chitosans showed identical spectra. Chitosans prepared through enzymatic deproteinization have practically the same acetylation degree but higher molecular weights compared to that obtained through chemical process. Antimicobial, antioxidant and antitumoral activitities of chitosan-M obtained by treatment with A21 proteases and chitosan-C obtained by alkaline treatment were investigated. Results showed that both chitosans inhibited the growth of most Gram-negative, Gram-positive bacteria and fungi tested. Furthermore, both chitosans exhibited antioxidant and antitumor activities which was dependent on the molecular weight. © 2014 Elsevier B.V.

Kammoun Bejar A.,University of Sfax | Boudhrioua Mihoubi N.,University of Sfax | Kechaou N.,University of Sfax
Food Chemistry | Year: 2012

The aims of this work were to determine chemical composition and sorption isotherms of Tunisian orange peel and leaves of the "Maltaise" variety. These by-products were found to be rich in fibre, soluble sugars, protein, minerals and phenols. The equilibrium moisture contents of "Maltaise" peel and leaves were measured using the static gravimetric method at three temperatures (40, 50 and 60°C) and in wide range of water activity (0.109-0.891). Desorption and adsorption data of peel and leaves were best fitted by the Peleg model at 40, 50 and 60°C. The net isosteric heats of desorption and adsorption were determined from sorption isotherms. For both peel and leaves, the net isosteric heat of desorption was higher than the net isosteric heat of adsorption and both decreased continuously with increasing of the equilibrium moisture content. © 2011 Elsevier Ltd. All rights reserved.

Ayadi L.,University of Sfax | Khabir A.,University of Sfax
Archives of Pathology and Laboratory Medicine | Year: 2010

Angiosarcomas are rare tumors that predominantly affect adults and elderly patients. Although angiosarcomas are well described in a variety of clinical settings, they have been poorly studied in children and little is known about their biology, natural history, or optimal treatment. Childhood angiosarcomas are exceedingly rare. The head and neck region and mediastinum seem to be the preferred locations. Most tumors are high-grade tumors.Vasoformative architecture is not always obvious on light microscopy requiring the benefit of immunohistochemical study. The differential diagnosis includes Kaposi sarcoma, epithelioid hemangioendothelioma, hemangiopericytoma, and spindle cell hemangioendothelioma whose prognosis is different. Complete resection is required for patients with localized tumors. Malignant vascular tumors are rare in children in the first 2 decades of life and when they do occur they seem to be more aggressive than in adults. Pathologic diagnosis is difficult particularly in poorly differentiated angiosarcomas requiring immunohistochemical study to confirm vascular differentiation.

Elleuch A.,University of Sfax | Boussetta A.,University of Sfax | Halouani K.,University of Sfax
Journal of Electroanalytical Chemistry | Year: 2012

The Direct Carbon Fuel Cell (DCFC) is a special type of high temperature fuel cell that directly uses solid carbon particles as anode and fuel. As an electrical power generator of power plants, it has a higher achievable efficiency (80%) than the Molten Carbonate (MCFC) and the Solid Oxide (SOFC) fuel cells, and has less emission than conventional coal-combustion power plants. In this paper, we propose a comparative study based on an analytical model for polarizations calculation in DCFC producing CO 2 and a mixture of (CO/CO 2) and using a carbonate melt (62 Li 2CO 3/38 K 2CO 3 mol%) as electrolyte. The obtained results indicate that when the CO is taken into account in the anode side, the DCFC performance increases by 15% compared to only CO 2 producing DCFC system at the same operating conditions (moves from 1350 W m -2 to 1550 W m -2). Simulations lead to understand the effect of the operating conditions (temperature, cathodic gas composition and inlet cathodic pressure) on the performance of the DCFC in order to solve all constraints preventing the development of this type of fuel cell. The comparison of the obtained results with data from literature illustrates a relatively good agreement with an absolute average deviation of about 4%. © 2012 Elsevier B.V. All rights reserved.

Kais S.,University of Sfax | Sami H.,University of Sfax
Renewable and Sustainable Energy Reviews | Year: 2016

The aim of this paper is to provide new empirical evidence on the impact of economic growth and energy use on carbon emissions (CO2 emissions) for fifty eight countries over the period 1990-2012 by using a panel data model. We also apply this model in order to implement three regional sub-groups; European and North Asian region, Latin American and Caribbean region, and the Middle Eastern, North African and sub-Saharan region. The results revealed that the energy use has a positive impact on the carbon dioxide emissions for all the panels. The impact of economic growth on the environment has received increased attention as global warming and other environmental problems become more serious. Indeed, the per capita GDP has a positive and statistically significant impact on carbon for the global panel, for the Europe and North Asia, and for the Middle Eastern, North Africa, and sub-Saharan Africa. Furthermore, our empirical results indicate the presence of an inverted U-shaped curve between carbon dioxide emissions and GDP per capita. © 2016 Elsevier Ltd. All rights reserved.

Tozri A.,University of Sfax | Tozri A.,CNRS Neel Institute | Dhahri E.,University of Sfax | Hlil E.K.,CNRS Neel Institute
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2011

We present the effect of vacancy and Na doping on the critical behavior in La0.8Pb0.2MnO3 via dc magnetization measurements. Critical exponents values for La0.8Pb 0.2MnO3 match well with those predicted for the three-dimensional Heisenberg model. The vacancy in La0.8Pb 0.1□0.1MnO3 does not alter the Heisenberg universality class. However, the critical isotherm exponent is slightly larger than predicted consistent with the presence of a Griffiths phase. For La 0.8Pb0.1Na0.1MnO3, we found that the critical exponents values are in a close agreement with those predicted for the mean-field theory. The reason for this behavior may be long-range interactions between spins in this system. © 2011 Elsevier B.V.

Akrout B.,University of Sfax | Mahdi W.,British Petroleum
IEEE Intelligent Vehicles Symposium, Proceedings | Year: 2013

The driver drowsiness detection used in human security systems aims to decrease the number of accidents. We describe in this paper an approach developed to detect the driver drowsiness state from a video-based system. Our approach uses a noninvasive method which excludes any human related elements. The latter calculates two geometric features to calculate a non-linearly and non-stationary signal. We analyze the signal extracted from the previous step by combining the two methods EMD (Empirical Mode Decomposition) and BP (Band Power) for filtering. This analysis is confirmed by the SVM (Support Vector Machine) to classify the driver alertness state. © 2013 IEEE.

Komatsu Y.,University of Sfax | Christian S.L.,Memorial University of Newfoundland | Ho N.,University of Sfax | Pongnopparat T.,University of Sfax | And 3 more authors.
Oncogene | Year: 2015

Oncolytic viruses exploit common molecular changes in cancer cells, which are not present in normal cells, to target and kill cancer cells. Ras transformation and defects in type I interferon (IFN)-mediated antiviral responses are known to be the major mechanisms underlying viral oncolysis. Previously, we demonstrated that oncogenic RAS/Mitogen-activated protein kinase kinase (Ras/MEK) activation suppresses the transcription of many IFN-inducible genes in human cancer cells, suggesting that Ras transformation underlies type I IFN defects in cancer cells. Here, we investigated how Ras/MEK downregulates IFN-induced transcription. By conducting promoter deletion analysis of IFN-inducible genes, namely guanylate-binding protein 2 and IFN gamma inducible protein 47 (Ifi47), we identified the IFN regulatory factor 1 (IRF1) binding site as the promoter region responsible for the regulation of transcription by MEK. MEK inhibition promoted transcription of the IFN-inducible genes in wild type mouse embryonic fibroblasts (MEFs), but not in IRF1 -/- MEFs, showing that IRF1 is involved in MEK-mediated downregulation of IFN-inducible genes. Furthermore, IRF1 protein expression was lower in RasV12 cells compared with vector control NIH3T3 cells, but was restored to equivalent levels by inhibition of MEK. Similarly, the restoration of IRF1 expression by MEK inhibition was observed in human cancer cells. IRF1 re-expression in human cancer cells caused cells to become resistant to infection by the oncolytic vesicular stomatitis virus strain. Together, this work demonstrates that Ras/MEK activation in cancer cells downregulates transcription of IFN-inducible genes by targeting IRF1 expression, resulting in increased susceptibility to viral oncolysis. © 2015 Macmillan Publishers Limited All rights reserved.

Ben Salah I.,University of Sfax | Njeh A.,Unite de Physique | Ben Ghozlen M.H.,University of Sfax
Ultrasonics | Year: 2012

An exact approach is used to investigate Rayleigh waves in a functionally graded piezoelectric material (FGPM) layer bonded to a semi infinite homogenous solid. The piezoelectric material is polarized when the six fold symmetry axis is put along the propagation direction x 1. The FGPM character imposes that the material properties change gradually with the thickness of the layer. Contrary to the analytical approach, the adopted numerical methods, including the ordinary differential equation (ODE) and the stiffness matrix method (SMM), treat separately the electrical and mechanical gradients. The influences of graded variations applied to FGPM film coefficients on the dispersion curves of Rayleigh waves are discussed. The effects of gradient coefficients on electromechanical coupling factor, displacement fields, stress distributions and electrical potential, are reported. The obtained deviations in comparison with the ungraded homogenous film are plotted with respect to the dimensionless wavenumber. Opposite effects are observed on the coupling factor when graded variations are applied separately. A particular attention has been devoted to the maximum of the coupling factor and it dependence on the stratification rate and the gradient coefficient. This work provides with a theoretical foundation for the design and practical applications of SAW devices with high performance. Crown Copyright © 2011 Published by Elsevier B.V. All rights reserved.

Golusin M.,Educons University | Ostojic A.,Novi Management | Latinovic S.,Imes Biogas | Jandric M.,University of Sfax | Ivanovic O.M.,Educons University
Renewable and Sustainable Energy Reviews | Year: 2012

Construction and operation of plants that produce energy from renewable energy sources is the subject for discussion in all the countries that have accepted the sustainable development concept and Kyoto protocol as their own development direction. Enlargement of the renewable energy production is clearly an imperative, but only economically viable construction and operation can result in long-term sustainability, which is initially the goal when deciding upon such investments. In line with this goal, this paper presents the estimation of the economic viability of constructing and operating biogas electricity plant on the farm Vizelj in Serbia. The timeframe for this estimation is from 2011 until 2020. This paper also presents all parameters which are necessary for performing this estimation, respectively, analysis of revenues and expenditures, projection of economic and financial flow, ratio analysis, dynamic and static analysis, and analysis of sensitivity of the project, i.e. impact of the changes in prices and raw material on the overall performance of the project. The observed investment is predicted to be financed from the EBRD's credit line for renewable energy in Western Balkans, while the total investment is estimated at Euro 958,000.00. After the performed economic assessment, the conclusion is that the observed investment in biogas electricity plant is very acceptable and it can serve as a role model for similar investments in the region. © 2011 Elsevier Ltd. All rights reserved.

Guidara S.,University of Sfax | Feki H.,University of Sfax | Abid Y.,University of Sfax
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2013

Single crystals of L-leucine L-leucinium picrate were grown by slow evaporation at room temperature and were characterized by X-ray powder diffraction study to confirm the crystalline nature of the synthesized compound. The optimized molecular structure, vibrational spectra and the optical properties were calculated by the Density Functional Theory (DFT) method using the B3LYP function with the 6-31G(d) basis set. Good consistency is found between the calculated results and the experimental structure, IR, and Raman spectra. The detailed interpretation of the vibrational modes was carried out. The natural bond orbital (NBO) analysis, confirms the occurrence of intermolecular hydrogen bonds that are responsible for the stabilization of the title compound, leading to high nonlinear optical (NLO) activity. The lowering in the HOMO and LUMO energy gap explains the eventual charge transfer interactions that take place within the molecules. © 2013 Elsevier B.V. All rights reserved.

Boukattaya M.,University of Sfax | Damak T.,University of Sfax | Jallouli M.,University of Sfax
International Journal of Automation and Computing | Year: 2011

This paper addresses the trajectory tracking control of a nonholonomic wheeled mobile manipulator with parameter uncertainties and disturbances. The proposed algorithm adopts a robust adaptive control strategy where parametric uncertainties are compensated by adaptive update techniques and the disturbances are suppressed. A kinematic controller is first designed to make the robot follow a desired end-effector and platform trajectories in task space coordinates simultaneously. Then, an adaptive control scheme is proposed, which ensures that the trajectories are accurately tracked even in the presence of external disturbances and uncertainties. The system stability and the convergence of tracking errors to zero are rigorously proven using Lyapunov theory. Simulations results are given to illustrate the effectiveness of the proposed robust adaptive control law in comparison with a sliding mode controller. © 2011 Institute of Automation, Chinese Academy of Sciences and Springer-Verlag Berlin Heidelberg.

Samet Y.,University of Sfax | Wali I.,University of Sfax | Abdelhedi R.,University of Sfax
Environmental Science and Pollution Research | Year: 2011

This work is first intended to optimize the experimental conditions for the maximum degradation of guaiacol (2-methoxyphenol) by Fenton's reagent, and second, to improve the process efficiency through the use of solar radiation. Guaiacol is considered as a model compound of pulp and paper mill effluent. The experiments were carried out in a laboratory-scale reactor subjected or not to solar radiation. Hydrogen peroxide solution was continuously introduced into the reactor at a constant flow rate. The kinetics of organic matter decay was evaluated by means of the chemical oxygen demand (COD) and the absorbance measurements. The experimental results showed that the Fenton and solar photo-Fenton systems lead successfully to 90% elimination of COD and absorbance at 604 nm from a guaiacol solution under particular experimental conditions. The COD removal always obeyed a pseudo-first-order kinetics. The effect of pH, temperature, H2O2 dosing rate, initial concentration of Fe2+, and initial COD was investigated using the Fenton process. The solar photo-Fenton system needed less time and consequently less quantity of H2O2. Under the optimum experimental conditions, the solar photo-Fenton process needs a dose of H2O2 40% lower than that used in the Fenton process to remove 90% of COD. © 2011 Springer-Verlag.

Matan M.,University of Sfax | Axelman E.,Thrombosis and Hemostasis Unit | Brenner B.,Thrombosis and Hemostasis Unit | Nadir Y.,Thrombosis and Hemostasis Unit
Human Reproduction | Year: 2013

STUDY QUESTIONWhat is the effect of estrogen on heparanase procogulant activity?SUMMARY ANSWEREstrogen increases heparanase procoagulant activity.WHAT IS KNOWN ALREADYEstrogen therapy increases the risk of thrombosis and was previously found to up-regulate heparanase expression. Heparanase is involved in angiogenesis and metastasis, and has been shown to form a complex with tissue factor (TF) and also shown to enhance the generation of factor Xa.STUDY DESIGN, SIZE, DURATIONA case-control study. Thirty-four healthy women using oral contraceptives (OC) and 41 women not using hormonal therapy and not pregnant per history were enrolled, over a 5-month period, at the Rambam Medical Center, Haifa, Israel. In vitro, estrogen receptor-positive (MCF-7) and -negative (MDA-231) cell lines were incubated with estrogen, tamoxifen and ICI-182.780 a pure estrogen receptor antagonist. The cell medium was evaluated for TF/heparanase complex activity, TF activity and heparanase procoagulant activity by chromogenic substrate.PARTICIPANTS/MATERIALS, SETTING, METHODSExclusion criteria included age <18 years, post-menopausal women, concomitant medications other than supplement minerals and vitamins, acute or chronic illness.MAIN RESULTS AND THE ROLE OF CHANCEThe study demonstrates increased risk of high heparanase procoagulant activity in OC users. When a cutoff level of 0.25 (absorbance 405-490 nm) was set, the odds ratio was 131 (P < 0.0001). When all results were studied by quartiles, in quartiles 3 and 4 the results were almost exclusively of the OC users (P < 0.0001). In cell cultures, estrogen and tamoxifen increased heparanase procoagulant activity in the medium of estrogen receptor-positive (MCF-7) cells.LIMITATIONS, REASONS FOR CAUTIONThe main limitation of the current study is that the two estrogens given to the women and cell cultures, ethinyl estradiol (EE) and 17-β-estradiol (E2), respectively, may have different effects on the coagulation system, although an increase in heparanase procoagulant activity was demonstrated in both of them. Although the sample size of the study group was limited, significant differences in the activation of the extrinsic coagulation pathway were demonstrated.WIDER IMPLICATIONS OF THE FINDINGSThe clinical relevance of the heparanase procoagulant activity assay as a screening tool in thrombophilia work-up should further be elucidated. © The Author 2013. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved.

Fakhfakh-Zouari N.,University of Sfax | Haddar A.,University of Sfax | Hmidet N.,University of Sfax | Frikha F.,University of Sfax | Nasri M.,University of Sfax
Process Biochemistry | Year: 2010

A new keratinolytic enzyme-producing bacterium was isolated from slaughter house polluted water and identified as Bacillus pumilus A1. Medium composition and culture conditions for the keratinases production by B. pumilus A1 were optimized using two statistical methods: Plackett-Burman design applied to find the key ingredients and conditions for the best yield of enzyme production and central composite design used to optimize the concentration of the five significant variables: feathers meal, soy peptone, NaCl, KCl, and KH2PO4. The medium optimization resulted in a 3.4-fold increase in keratinase production (87.73 U/ml) compared to that of the initial medium (25.9 U/ml). The zymography analysis shows the presence of at least five keratinolytic enzymes. The keratinolytic activity of the extracellular proteinases was examined by incubation with non-autoclaved chicken feathers. Complete solubilisation of whole feathers was observed after a 6-h incubation at temperatures ranging from 45 °C to 60 °C. The crude enzyme exhibited maximal activity at 60 °C and pH 8.5 or 55 °C and pH 9.0 using casein or keratin as substrates, respectively. © 2009 Elsevier Ltd. All rights reserved.

Boubakri A.,University of Sfax | Haddar N.,University of Sfax | Elleuch K.,University of Sfax | Bienvenu Y.,MINES ParisTech
Materials and Design | Year: 2010

In this study, impact of environmental aging conditions on the mechanical properties of thermoplastic polyurethane (TPU) was investigated. Especially, effect of temperature on water diffusion has been studied. Water-sorption experiments, tensile test and dynamic mechanical thermal analysis (DMTA) were performed after immersion in distilled water at different temperatures (25, 70 and 90°C). The sorption process was analyzed by gravimetric measurements at different temperatures. Also, diffusion coefficients of solvent molecules in the TPU samples were identified. Therefore the activation energy and the mixing enthalpy were deduced. The aging impact on some mechanical properties of this material has been investigated after various aging cycles. Degradation of mechanical properties was observed. In fact, elastic modulus and stress at 200% of strain were decreased. It was also shown that such degradation largely depends on both aging temperature and aging immersion duration. The storage modulus (E') was also affected by the hygrothermal (HT) environment. The modification of mechanical properties seems to be well correlated to structural observations obtained from scanning electron microscopy (SEM) photographs. Finally, through thermal aging experiments, it was deduced that the combination of temperature with water seems to be a major factor of TPU degradation. © 2010 Elsevier Ltd.

Cross W.M.,University of Sfax | Bloomer M.J.,Monash University
International Journal of Mental Health Nursing | Year: 2010

We are often confronted with the dilemmas of interacting with people from different cultural backgrounds. How do we ensure that we meet their needs, if they have some barriers to communicating those needs? This project explores the communication mechanisms used by mental health clinicians, to explore how they modify their communication to reconcile cultural differences and promote self-disclosure. It also identifies the practical experiences that have enlightened clinicians' practice when interacting with culturally and linguistically diverse (CALD) groups. Through focus groups, mental health clinicians were probed about their experiences with CALD groups and the methods used to facilitate communication. Clinicians were working in either acute adult inpatient or community settings in a large metropolitan health service. Fifty-three clinicians formed 7 focus groups. In the focus groups, clinicians were asked about their perceptions of communication with CALD clients. Guided questions were used. All focus groups were audio-taped and transcribed. Two distinct themes emerged. They were 'respect' and 'cultural understanding'. The clinicians recognized that showing and maintaining respect for the CALD client, and their families significantly impacted on the development of a therapeutic relationship. Showing cultural understanding and acceptance for difference also enhanced communication. © 2010 The Authors. Journal compilation © 2010 Australian College of Mental Health Nurses Inc.

Zarai Jaouadi N.,University of Sfax | Jaouadi B.,University of Sfax | Aghajari N.,CNRS Molecular Chemistry Laboratory | Bejar S.,University of Sfax
Bioresource Technology | Year: 2012

The sapB gene encoding for Bacillus pumilus CBS protease (SAPB) and the triple mutated sapB-L31I/T33S/N99Y gene were cloned and overexpressed in the protease-deficient Bacillus subtilis DB430 using an Escherichia coli- Bacillus shuttle vector pBSMuL2. The 34,625.13 and 34,675.11-Da enzymes were purified from the culture supernatant of B. subtilis expressing the wild-type and mutated genes, respectively. The purified proteases showed the same N-terminal sequences and biochemical properties of those expressed in E. coli. Further investigations demonstrated that, compared to wild-type and other proteases, SAPB-L31I/T33S/N99Y had the highest catalytic efficiency and the best degree of hydrolysis. The mutant enzyme was also noted to exhibit a number of newly explored properties that are highly valued in the marketplace, namely considerable stability to detergents, higher resistance towards organic solvents, and potent dehairing ability. Overall, the findings indicated that SAPB-L31I/T33S/N99Y is a promising candidate for future use in a wide range of industrial and commercial applications. © 2011 Elsevier Ltd.

Xiang S.D.,University of Sfax | Wilson K.,University of Sfax | Day S.,University of Sfax | Fuchsberger M.,University of Sfax | Plebanski M.,University of Sfax
Methods | Year: 2013

It has recently become clear that nanoparticle size is a major determinant for how antigen presenting cells (APCs), and specifically dendritic cells (DC) recognize and handle particles, and hence a critical parameter for the formulation of particulate vaccines that aim to induce immunity by targeting DC. Our previous studies in mice and sheep have shown polystyrene nanoparticles of 40-50nm (PSNPs) with covalently bound antigen offer a new class of vaccines, which contain only 2 elements, antigen and particle, and no added inflammatory stimuli, but evoke very potent combined CD8 T cell and antibody responses. Herein we have optimized the methods for antigen conjugation to PSNPs to controllably promote a single antigen (protein or peptide) layer coating on the nanoparticle. Surprisingly, these nanovaccines not only continued to induce high levels of CD8 T cells in vivo, but were further more potent antibody inducers than nanoparticles containing multiple antigen layers. Addressing the issue of antigen loading on PSNPs, we found an optimal range, above or below which immunogenicity is changed either for antibodies or CD8 T cells. The mechanism behind the induction of high levels of CD8 T cells was further explored by assessing the DC subset that takes up the PSNPs in vivo, and these were found to be preferentially CD8+ CD11c+ DC in the lymph node draining the injection site. Since the levels of induced antibodies were highly elevated, and CD8+ DC do not traditionally induce antibodies, we further sought to find if, despite no detectable inflammation at the injection site, the PSNPs may perhaps induce inflammatory cytokines locally in the lymph node after injection, or systemically in sera, resulting in an adjuvant effect. The initial findings presented herein show no detectable induction of the key inflammatory cytokines such as TNF-α, IL-1 or IL-6, suggesting a novel "non-inflammatory" adjuvant mechanism. © 2013 Elsevier Inc.

Feki-Tounsi M.,University of Sfax | Hamza-Chaffai A.,University of Sfax
Environmental Science and Pollution Research | Year: 2014

Bladder cancer is a significant disease, the rates of which have increased over the few last years. However, its etiology remains as yet undefined. Cadmium, a widespread environmental carcinogen that has received considerable interest, presents evidence as a possible cause of bladder cancer. A literature review was conducted from the years 1984–2013 to study the accumulated evidence for cadmium as a possible cause of bladder cancer, including routes of cadmium exposure, accumulation, toxicity, carcinogenicity, and evidence from epidemiological and experimental studies. Special reference is devoted to cadmium nephrotoxicity, which illustrates how cadmium exerts its effects on the transitional epithelium of the urinary tract. Mechanisms of carcinogenesis are discussed. The effects of cadmium on gene expression in urothelial cells exposed to cadmium are also addressed. Despite different methodologies, several epidemiologic and nephrotoxicity studies of cadmium indicate that occupational exposure to cadmium is associated with increased risk of bladder cancer and provide additional evidence that cadmium is a potential toxic element in urothelial cells. In vitro studies provide further evidence that cadmium is involved in urothelial carcinogenesis. Animal studies encounter several problems such as morphology differences between species. Among the complex mechanisms of cadmium carcinogenesis, gene expression deregulation is the subject of recent studies on bladder cadmium-induced carcinogenesis. Further research, however, will be required to promise a better understanding of the mechanisms underlying cadmium carcinogenesis and to establish the precise role of cadmium in this important malignancy. © 2014, Springer-Verlag Berlin Heidelberg.

Zhani K.,University of Sfax | Ben Bacha H.,King Saud University
Desalination and Water Treatment | Year: 2010

This paper tackles an optimization approach in order to boost the fresh water production of the SMCEC (Solar Multiple Condensation Evaporation Cycle) unit which is located at Sfax's engineering national school in Tunisia. This optimization approach is based upon the above mentioned design's improvement through adding into it a flat plate solar air collector and a humidifier. Then, the humidification dehumidification (HD) developed process is essentially composed of five components: a flat plate solar air collector, a flat plate solar water collector, a humidifier, an evaporation tower and a condensation tower. A global mathematical model based on heat and mass transfers is developed to investigate both the effect of different operating modes and that of the variation of functioning parameters and weather conditions on the fresh water production. The fresh water production of the most effective operating mode is compared to the SMCEC unit and as a result, it transpires that the fresh water production of the most effective operating mode has increased with comparison to the SMCEC production. © 2010 Desalination Publications.

Peinado J.R.,University of Sfax | Pardo M.,Complejo Hospitalario Universitario Of Santiago Chus | Pardo M.,CIBER ISCIII | De la Rosa O.,Cellerix TM | And 2 more authors.
Proteomics | Year: 2012

The original concept of adipose tissue as an inert storage depot for the excess of energy has evolved over the last years and it is now considered as one of the most important organs regulating body homeostasis. This conceptual change has been supported by the demonstration that adipose tissue serves as a major endocrine organ, producing a wide variety of bioactive molecules, collectively termed adipokines, with endocrine, paracrine and autocrine activities. Adipose tissue is indeed a complex organ wherein mature adipocytes coexist with the various cell types comprising the stromal-vascular fraction (SVF), including preadipocytes, adipose-derived stem cells, perivascular cells, and blood cells. It is known that not only mature adipocytes but also the components of SVF produce adipokines. Furthermore, adipokine production, proliferative and metabolic activities and response to regulatory signals (i.e. insulin, catecholamines) differ between the different fat depots, which have been proposed to underlie their distinct association to specific diseases. Herein, we discuss the recent proteomic studies on adipose tissue focused on the analysis of the separate cellular components and their secretory products, with the aim of identifying the basic features and the contribution of each component to different adipose tissue-associated pathologies. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zhani K.,University of Sfax | Ben Bacha H.,King Saud University
Desalination and Water Treatment | Year: 2010

This paper deals with modeling and simulation of a new design of the SMCEC (Solar Multiple Condensation Evaporation Cycle) desalination unit using solar energy. The newly designed system is basically composed of a flat plate solar air collector, a flat plate solar water collector, a humidifier, an evaporation tower and a condensation tower. A mathematical model based on heat and mass transfers in each component of the unit is developed and simulated using C++ software in a steady state regime. The numerical model is used to investigate the steady state behavior of each component of the unit exposed to a variation of the entrance parameters and meteorological conditions. This theoretical model is expected to help in predicting the behavior of the unit in various operating and climatic conditions. Besides, it would be useful in enhancing the performance of such unit. © 2010 Desalination Publications.

Ayadi O.,University of Sfax | Cheikhrouhou N.,Ecole Polytechnique Federale de Lausanne | Masmoudi F.,University of Sfax
Computers and Industrial Engineering | Year: 2013

Assessing customer trust in suppliers with regards to its influencing factors is an important open issue in supply chain management literature. In this paper, a customer trust index is designed as the trust level arising from the information sharing degree and quality, related to the information shared by a supplier with his customer. The customer trust level is evaluated using a fuzzy decision support system integrating information sharing dimensions. The core is a rule-based system designed using the results of questionnaires and interviews with supply chain experts. Several tests were generated in order to analyze the impact of the different information sharing attributes on the customer trust index. The developed approach is then applied to a real supply chain from the textile industry. Results show large differences of weight and impact between the different information-related factors that build the customer trust index. It is also shown that the proposed system has an important role in ensuring the objectivity of the trust assessment process and in helping decision makers evaluate their business partners. © 2013 Elsevier B.V. All rights reserved.

Elrebii M.,University of Sfax | Boufi S.,University of Sfax
Journal of Industrial and Engineering Chemistry | Year: 2014

Surfactant-free waterborne hybrid alkyd-acrylic dispersions with a solid content of 40% were synthesized, characterized and their long term stability investigated. Spontaneous emulsification of the ensuing hybrid resin was achieved, following the addition of base aqueous solution such as NH3, triethylamine (TEA) or NaOH that neutralize the carboxyl groups. The key role of the carboxylic groups in the stabilization process was discussed and the effect of their content on the properties of the dispersion was analyzed. According to the neutralizing base, the particle size of the dispersion, its viscosity and the hydrolytic resistance of the hybrid resin were greatly altered. © 2013 The Korean Society of Industrial and Engineering Chemistry.

Cherif S.,University of Sfax
Lipids in health and disease | Year: 2011

Bacterial lipases received much attention for their substrate specificity and their ability to function in extreme environments (pH, temperature...). Many staphylococci produced lipases which were released into the culture medium. Reports of thermostable lipases from Staphylococcus sp. and active in alkaline conditions are not previously described. A newly soil-isolated Staphylococcus sp. strain ESW secretes an induced lipase in the culture medium. The effects of temperature, pH and various components in a detergent on the activity and stability of Staphylococcus sp. lipase (SL1) were studied in a preliminary evaluation for use in detergent formulation solutions. The enzyme was highly active over a wide range of pH from 9.0 to 13.0, with an optimum at pH 12.0. The relative activity at pH 13.0 was about 60% of that obtained at pH 12.0. It exhibited maximal activity at 60°C. This novel lipase, showed extreme stability towards non-ionic and anionic surfactants after pre-incubation for 1 h at 40°C, and relative stability towards oxidizing agents. Additionally, the crude enzyme showed excellent stability and compatibility with various commercial solid and liquid detergents. These properties added to the high activity in high alkaline pH make this novel lipase an ideal choice for application in detergent formulations.

Mongi S.,University of Sfax | Mahfoud M.,Annaba University | Amel B.,Annaba University | Kamel J.,Biochemistry Laboratory | Abdelfattah E.F.,University of Sfax
Ecotoxicology and Environmental Safety | Year: 2011

Deltamethrin is a synthetic pyrethroid insecticide. It is known for its wide toxic manifestations. The present experiment pertains to the protective role of vitamin C against haematological and biochemical toxicity induced by deltamethrin during 4 weeks. Male Wistar rats were divided into four groups of eight each: Group I served as control rats; Group II received deltamethrin (1.28. mg/kg BW) in drinking water. Group III received both deltamethrin and vitamin C (200. mg/kg BW; by i.p. injection); Group IV received vitamin C (200. mg/kg BW). Exposure of rats to deltamethrin caused significant changes of some haematological parameters (red blood cells (RBC), haemoglobin (Hb), haematocrit (Ht), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), platelet (Plt) and white blood cells (WBC)) in treated rats compared to controls. Significant increases in the levels of hepatic markers enzymes (alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), γ-Glutamyl transpeptidase (γ-GT)). Furthermore, renal markers such as urea and creatinine were increased in deltamethrin treated rats. Additionally, serum cholesterol and lipid peroxidation were significantly enhanced. Co-administration of vitamin C to the group III restored all the parameters cited above to near-normal values. Therefore, our investigation revealed that vitamin C appeared to be a promising agent for protection against deltamethrin-induced toxicity. © 2011.

Dhahri H.,University of Sfax | Alimi A.M.,University of Sfax | Abraham A.,VSB - Technical University of Ostrava | Abraham A.,Network Intelligence
Neurocomputing | Year: 2012

This paper proposes a hierarchical multi-dimensional differential evolution (HMDDE) algorithm, which is an automatic computational frame work for the optimization of beta basis function neural network (BBFNN) wherein the neural network architecture, weights connection, learning algorithm and its parameters are adapted according to the problem. In the HMDDE-designed neural network, the number of individuals of the population multi-dimensions is the number of beta neural networks. The population of HMDDE forms multiple beta networks with different structures at the higher level and each individual of the previous population is optimized at a lower hierarchical level to improve the performance of each individual. For the beta neural network consisting of m neurons, n individuals (different lengths) are formed in the upper level to optimize the structure of the beta neural network. In the lower level, the population within the same length is to optimize the free parameters of the beta neural network. To evaluate the comparative performance, we used benchmark problems drawn from identification system and time series prediction area. Empirical results illustrate that the HMDDE produces a better generalization performance. © 2012 Elsevier B.V.

Hanwella R.,University of Sfax | De Silva V.,University of Sfax
Social Psychiatry and Psychiatric Epidemiology | Year: 2012

Purpose: To compare the mental health problems of Special Forces with regular forces engaged in combat in the Sri Lanka Navy (SLN). Methods: A population-based descriptive study was carried out to compare the mental health problems of Special Forces with regular forces in the Sri Lanka Navy (SLN) deployed in combat areas for at least 1 year. Participants were selected by simple random sampling. The outcome measures were common mental disorder measured using the General Health Questionnaire, PTSD, fatigue, multiple physical symptoms and hazardous alcohol use. Results: Overall exposure to potentially traumatic events was high in both groups, with Special Forces experiencing significantly more traumatic events. More than 80% of the Special Forces had experiences of discharging weapons in direct combat, engaging in combat with enemy vessels and seeing the dead or wounded. Special Forces had significantly less common mental disorders, fatigue and fair or poor general health than regular forces. Fair or poor general health (21.1%) and fatigue (18.4%) were the commonest problems in the regular forces. Hazardous drinking was the commonest mental health problem among the Special Forces (17%). Prevalence of PTSD was 1.9% in the Special Forces and 2.9% among the regular forces. Exposure to traumatic events and problems with family life were identified as risk factors. Conclusions: Elite troops suffered less negative mental health consequences than regular forces despite higher combat exposure. Comradeship and unit cohesion protected Special Forces from negative mental health outcome of combat. © Springer-Verlag 2011.

Fersi G.,University of Sfax | Louati W.,University of Sfax | Ben Jemaa M.,University of Sfax
Wireless Networks | Year: 2013

Recent advances in Wireless Sensor Networks (WSN) have led to a great breakthrough in sensors design and features. These technological novelties have brought additional challenges to WSN. Sensornets are seeking for new approaches for efficient data routing and management. The last few years have witnessed the emergence of several approaches that build Distributed Hash Tables (DHTs) over WSN. DHTs are initially conceived for efficient data lookup in large-scale wired networks. The main objective of this combination is to manage location-independent data and nodes identification. DHT mapping over WSN brings however new challenges. This paper presents an analytical survey on applying DHT techniques in WSNs. It describes existing DHT-based routing and data management protocols and includes a detailed classification of them. © 2012 Springer Science+Business Media, LLC.

Industrial effl uents treatment was investigated using ceramic Microfiltration (MF) and Ultrafiltration (UF) tubular membranes. The comparison of performances between commercial ceramic membranes based on alumina material and elaborated ones based on Tunisian clay material was studied. MF and UF tests applied to cuttlefish effl uent treatment were carried out respectively with 0.2 μ and 5 nm commercial membranes and 0.18 μ and 15 nm prepared membranes. The results show that for the two processes, the performances in term of permeate fl ux and quality of the treated wastewater using clay membranes was a little better than that obtained with commercial one. © 2012 Desalination Publications.

Baklouti M.,University of Sfax | Elleuch R.,University of Sfax
Journal of Mechanical Science and Technology | Year: 2012

Brass alloy is widely used because of some attractive properties such as high electrical and thermal conductivity. But its fatigue performance after surface treatment is not very well explored in literature. Thus, in the present work, particular emphasis was given to the influence of surface treatment by shot peening on the fatigue life of brass alloy, throughout surface roughness and microstructural evolution. Fatigue tests were performed on unpeened, peened and peened then polished specimens. Various times of surface hardening treatment as 30, 60 and 120 min were considered. Experimental results reveal that the fatigue life of peened brass alloy decrease for all studied hardening treatment conditions. Surface roughness and microstructural properties showed large sensitivity to the shot peening process of brass alloy. © 2012 The Korean Society of Mechanical Engineers and Springer-Verlag Berlin Heidelberg.

Omheni N.,University of Sfax | Kacem A.H.,University of Sfax
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016

Many students suffer of online reading difficulties because of their low abilities of text comprehension. Several educators tried to set strategies to support learners during their online reading. In current work, we present an online reading environment where students can enroll in virtual reading class, to read and annotate their documents. Based on students’ annotation traces, we build their personality profiles which reflect their level of reading performance. Given the students’ reading abilities, we share the annotations of skilled readers with those having problems of text comprehension. The experimental results show the efficiency of the proposed approach to support learners with low reading abilities. © Springer International Publishing Switzerland 2016.

Baello S.,King's College | Iqbal M.,King's College | Bloise E.,King's College | Javam M.,King's College | And 3 more authors.
Endocrinology | Year: 2014

P-glycoprotein (P-gp), an efflux transporter encoded by the abcb1 gene, protects the developing fetal brain. Levels of P-gp in endothelial cells of the blood-brain barrier (BBB) increase dramatically during the period of peak brain growth. This is coincident with increased release of TGF-β1 by astrocytes and neurons. Although TGF-β1 has been shown to modulate P-gp activity in a number of cell types, little is known about how TGF-β1 regulates brain protection. In the present study, we hypothesized that TGF-β1 increases abcb1 expression and P-gp activity in fetal and postnatal BBB in an age-dependent manner. We found TGF-β1 to potently regulate abcb1 mRNA and P-gp function. TGF-β1 increased P-gp function in brain endothelial cells (BECs) derived from fetal and postnatal male guinea pigs. These effects were more pronounced earlier in gestation when compared with BECs derived postnatally. To investigate the signaling pathways involved, BECs derived at gestational day 50 and postnatal day 14 were exposed to ALK1 and ALK5 inhibitors and agonists. Through inhibition of ALK5, we demonstrated that ALK5 is required for the TGF-β1 effects on P-gp function. Activation of ALK1, by the agonist BMP-9, produced similar results to TGF-β1 on P-gp function. However, TGF-β1 signaling through the ALK1 pathway is age-dependent as dorsomorphin, an ALK1 inhibitor, attenuated TGF-β1-mediated effects in BECs derived at postnatal day 14 but not in those derived at gestational day 50. In conclusion, TGF-β1 regulates P-gp at the fetal and neonatal BBB and both ALK5 and ALK1 pathways are implicated in the regulation of P-gp function. Aberrations in TGF-β1 levels at the developing BBB may lead to substantial changes in fetal brain exposure to P-gp substrates, triggering consequences for brain development. Copyright © 2014 by the Endocrine Society.

Neila M.B.R.,University of Sfax | Tarak D.,University of Sfax
International Journal of Automation and Computing | Year: 2011

In order to apply the terminal sliding mode control to robot manipulators, prior knowledge of the exact upper bound of parameter uncertainties, and external disturbances is necessary. However, this bound will not be easily determined because of the complexity and unpredictability of the structure of uncertainties in the dynamics of the robot. To resolve this problem in robot control, we propose a new robust adaptive terminal sliding mode control for tracking problems in robotic manipulators. By applying this adaptive controller, prior knowledge is not required because the controller is able to estimate the upper bound of uncertainties and disturbances. Also, the proposed controller can eliminate the chattering effect without losing the robustness property. The stability of the control algorithm can be easily verified by using Lyapunov theory. The proposed controller is tested in simulation on a two-degree-of-freedom robot to prove its effectiveness. © 2011 Institute of Automation, Chinese Academy of Sciences and Springer-Verlag Berlin Heidelberg.

Goldar S.,University of Sfax | Goldar S.,Tabriz University of Medical Sciences | Khaniani M.S.,University of Sfax | Derakhshan S.M.,University of Sfax | Baradaran B.,Tabriz University of Medical Sciences
Asian Pacific Journal of Cancer Prevention | Year: 2015

Programmed cell death (PCD) or apoptosis is a mechanism which is crucial for all multicellular organisms to control cell proliferation and maintain tissue homeostasis as well as eliminate harmful or unnecessary cells from an organism. Defects in the physiological mechanisms of apoptosis may contribute to different human diseases like cancer. Identification of the mechanisms of apoptosis and its effector proteins as well as the genes responsible for apoptosis has provided a new opportunity to discover and develop novel agents that can increase the sensitivity of cancer cells to undergo apoptosis or reset their apoptotic threshold. These novel targeted therapies include those targeting anti-apoptotic Bcl-2 family members, p53, the extrinsic pathway, FLICE-inhibitory protein (c-FLIP), inhibitor of apoptosis (IAP) proteins, and the caspases. In recent years a number of these novel agents have been assessed in preclinical and clinical trials. In this review, we introduce some of the key regulatory molecules that control the apoptotic pathways, extrinsic and intrinsic death receptors, discuss how defects in apoptotic pathways contribute to cancer, and list several agents being developed to target apoptosis.

Bouri S.,University of Sfax | Dhia H.B.,University of Sfax
Comptes Rendus - Geoscience | Year: 2010

With the increased demand for groundwater resulting from fast demographic growth, accelerated urbanization, economic and agricultural activity diversification, and the increase of per capita consumption, ground water resources, in particular in coastal regions, remain relatively low, compared to demand. The groundwater quality and piezometric variations result mainly from intensive exploitation, agricultural activities and the intrusion of seawater. This phenomenon is observed mostly in semi-arid areas, such as the oriental Sahel of Tunisia, where an apparent reduction in rainfall in recent years can be seen. Groundwater becomes overexploited especially as its natural recharge by rainwater does not succeed in maintaining the hydrologic balance. The imbalance between water demand and resources induces the degradation of the water quality. In such a case, the artificial recharge of water-table aquifers by water from dams is a credible alternative to improve the hydrodynamic and physicochemical conditions of the groundwater. Like most coastal aquifers, the Teboulba water-table aquifer is threatened by overexploitation for at least three decades. This threat appears by a considerable piezometric level drop and by water salinisation, due to seawater intrusion. Given this alarming situation, since 1971, artificial recharge through wells with surface water from a dam was tested in order to restore the water levels and to improve water quality. The piezometric and chemical surveys of the Teboulba aquifer permitted one to describe the temporal and spatial piezometric and geochemical conditions of the aquifer and to show the effect of the artificial recharge. Indeed, the artificial recharge undertaken since 1971 made the geochemical and piezometric conditions of the Teboulba aquifer improve. This example is a rare, well-documented case-study of the benefits of artificial recharge in a coastal aquifer, over the long term. © 2009 Académie des sciences.

Omri A.,University of Sfax | Benzina M.,University of Sfax
Alexandria Engineering Journal | Year: 2012

In this paper, activated carbon was prepared from Ziziphus spina-christi seeds (ZSAC) to remove Mn(II) from aqueous solutions. To characterize the adsorptive characteristics of the produced active carbon, surface area was calculated using the standard Brunauer-Emmet-Teller method. The microstructures of the resultant activated carbon were observed by with scanning electron micrographs. Chemical characterization of the surface resultant activated carbon was studied by Fourier Transform Infrared Spectroscopy. The effects of pH, initial metal ion concentration and temperature on the adsorption performance of ZSAC for Mn(II) ions were examined by batch method. The adsorption equilibrium data were analyzed by Langmuir, Freundlich and Temkin isotherm models. We concluded that maximum adsorption capacity of manganese calculated from Langmuir isotherm was around 172 mg/g. © 2012 Faculty of Engineering, Alexandria University. Production and hosting by Elsevier B.V. All rights reserved.

Kammoun N.G.,University of Sfax | Zarrouk W.,University of Sfax
International Journal of Food Science and Technology | Year: 2012

This study aims to evaluate some Tunisian olive genetic resources using fatty acid, triacyglycerol and sterolic compositions and to classify the cultivars according to their fruit genotype and to their respective geographical origin (North, Centre and South). manova results showed that the studied cultivars presented highly significant differences regarding all the variables (P<0.01). The most discriminant variables of fatty acids are C17:1 (F=98.468), C16:0 (F=92.994), C18:1 (F=60.865), C18:1/C18:2 (F=44.632) and C18:2 (F=40.167); those of triacylglycerols are POP (F=123.34), LLL (F=122.944), LnLO (F=98.363), POO (F=93.357) and LOO (F=90.42), while sitostanol (F=289.171), campestanol (F=192.792) and campesterol (F=160.724) have the higher discriminant power among sterol compounds. Principal component analysis (PCA) was performed on the data of each chemical parameter to explore their usefulness for the discrimination of eleven monovarietal olive oils. Best differentiations among cultivars were obtained with triacyglycerol and sterolic compositions. The spatial distribution of the different oil samples using all the collected data showed a good discrimination among olive cultivars. A strong resolution between the samples according to the geographical origin was obtained by means of factorial discriminant analysis (FDA) (λ=0.002). Comparisons of the distances between classes were statistically significant (Fisher tests; P<0.0001), and 90.91% of cross-validated grouped cases are correctly classified. The obtained results could become an important tool for sorting out oils to a single cultivar or to a specific geographical area. © 2012 Institute of Food Science and Technology.

Fersi G.,University of Sfax
Proceedings - IEEE International Conference on Distributed Computing in Sensor Systems, DCOSS 2015 | Year: 2015

The significant progress in smart devices has lead to the shifting of actual Internet to the Internet of Things (IoT). Internet of Things is invading our real lives. In this new Internet vision, trillions of smart dynamic objects and areas will be connected to the Internet and interact between each others to achieve common applications. This new Internet vision requires suitable IoT infrastructure that offers the main Internet of Things functionalities to facilitate the development of IoT applications. Middleware is the software layer between technological and application layers. It is mainly used to afford common services and functions to applications and to abstract implementation details to ease more complex application development. In this paper, we review the main challenges facing Internet of Things middleware and survey the most well known middleware that have been proposed in this field. © 2015 IEEE.

Bertram J.E.A.,University of Sfax | Hasaneini S.J.,University of Calgary
Journal of Experimental Biology | Year: 2013

As one of the most energetically demanding daily activities, locomotion has attracted substantial investigative attention. Although legged locomotion has been well described, it is currently not well understood. Looking at energy accounting might be a good pathway with which to solve this problem. One relatively simple way of analyzing energy management is to look directly at the flow of mechanical energy into and out of the system, in terms of costs and losses (with some attention to the mechanisms responsible for this flow). In this commentary we argue that a key source of energetic loss has largely been neglected: the redirection of body motion from downward to upward at each step. We discuss the role of this loss and the compensating energetic costs, identifying some of the general features of the trade-offs that determine gait optimization strategies. We find that even at a conceptual level, a focus on the main mechanism of loss and the strategies available to the organism to effectively compensate for losses can yield substantial insight into observations as diverse as the functional limits of a playground swing through to the strikingly different effect of reduced gravity on human walking and running. Such insight changes the interpretation of fundamental features of leg function, such as push-off timing and the role of elastic deflection during stance. © 2013. Published by The Company of Biologists Ltd.

Elleuch W.,University of Sfax
International Conference on Wireless and Mobile Computing, Networking and Communications | Year: 2013

Several models and architectures are proposed to support multiparty communication over IP. Even if some of these solutions support large number of participants using a conference server, solutions that base their media distribution on peers are adapted to support only small conferencing groups. Deploying multimedia communication based on WebRTC API for more than browser-to-browser connection is not inherently supported and creates new challenge in terms of media stream distribution as well as membership and conferencing operation control overhead. Many conference models presented in this paper can support multi-party communication between endpoints over an IP networks. Otherwise, the use of WebRTC technology require direct P2P media negotiation between participants as well as signaling interaction with the Server to manage the conference. This paper introduces two specific conference models adapted to support WebRTC communication between browsers for both small scale and large scale conference. The proposed abstract protocols included in this work implements conference creation and browser joining/leaving and can be mapped using SIP/DSP primitives. © 2013 IEEE.

Choura M.,University of Sfax | Rebai A.,University of Sfax
Journal of Receptors and Signal Transduction | Year: 2012

Proteinprotein interaction (PPI) network analysis has been considered as a useful approach to explore the mechanisms of complex diseases, such as cancer. To date, many proteins have been reported to involve in the development of cancer. Exploration of cancer proteins in the human PPI network may provide important biological information to uncover molecular mechanisms of cancer. Here, we have explored network characteristics (including degree, betweenness, clustering coefficient and shortest-path distance) of cancer proteins of the human nuclear and tyrosine kinases receptors network (NR-RTK) constructed in our earlier work. We found that the network topology of cancer proteins in this network have some specific features. Relative to the non-cancer proteins, the cancer proteins have likely higher degree, higher betweenness, similar clustering coefficient and similar shortest-path distance. Finally, we found that the cancer proteins were involved mainly in signalling pathways which dysfunction is directly related to cancer onset. These findings are helpful for cancer candidate protein prioritization and verification, and identification of key pathways involved in cancer disease. © 2012 Informa Healthcare USA, Inc.

Mohd Salih P.A.K.,University of Sfax
Medical Journal of Malaysia | Year: 2011

This study was conducted to describe corneal endothelial cell density and morphology in Malay eyes. Non-contact specular microscopy was performed in 125 eyes of 125 Malay volunteers, aged 20-87 years. Studied parameters included endothelial cell density (CD), mean cell area (MCA), coefficient of variation (CV) in cell area, as well as hexagonal appearance of the cells. Mean endothelial cell density in the study population was 2648 ± 310 cell/mm 2. Mean CA, CV and percentage of hexagonal cells were 382.8 ± 47.7μm 2, 58.1 ± 22.6, 44.3% ± 11.5% respectively. There was a statistically significant decrease in endothelial cell density (correlation - 0.300, P = 0.001) and CV in cell size (correlation-0.208, P = 0.02) with age. There was a statistically significant increase in mean cell area (correlation 0.300, P = 0.001) with increasing age. The correlation between age and percentage of hexagonal cells was insignificant (correlation 0.074, P = 0.41). In conclusion, a consistent decrease was noted in the endothelial cell density with increasing age. The differences in endothelial cell density between genders were statistically insignificant.

Zaghouene H.,University of Sfax | Khemakhem H.,University of Sfax | Simon A.,CNRS Laboratory of Condensed Matter Chemistry, Bordeaux
Ceramics International | Year: 2012

The (Ba 0.95Ca 0.05) 0.8875Bi 0.075TiO 3 ceramic composition was prepared using the conventional mixed-oxide technique. X-ray diffraction at room temperature and dielectric permittivity in the temperature range from 85 to 450 K and frequency range from 10 2 to 2 × 10 5 Hz, respectively, were studied. The X-ray spectra were investigated by profile refinement technique with the use of specialized software at room temperature, the (Ba 0.95Ca 0.05) 0.8875Bi 0.075TiO 3 composition crystallizes in quadratic perovskite structure. The dielectric measurements show classical ferroelectric behavior. The pyroelectric and piezoelectric results confirm the dielectric measurements. The pyroelectric coefficient is about 69.2 nC/cm 2 K at the transition temperature (T C = 367 K). The piezoelectric constant is d 31 = 31.1 pC/N and the electromechanical coupling factor is k P = 0.14679. Raman spectra of (Ba 0.95Ca 0.05) 0.8875Bi 0.075TiO 3 ceramic were taken at various temperatures and measured over the wave number range from 50 to 1000 cm -1. All the Raman bands were assigned as the transitional modes of Ba 2+, Ca 2+, Bi 3+ and Ti 4+ cations. The temperature evolution of Raman spectra across the transition shows an important evolution characterizing the disorder of the high temperature phase. © 2011 Elsevier Ltd and Techna Group S.r.l.

Balti R.,University of Sfax | Nedjar-Arroume N.,Laboratoire Of Procedes Biologiques | Bougatef A.,University of Sfax | Guillochon D.,Laboratoire Of Procedes Biologiques | Nasri M.,University of Sfax
Food Research International | Year: 2010

The angiotensin I-converting enzyme (ACE) inhibitory activities of protein hydrolysates prepared from muscle of cuttlefish (Sepia officinalis) by treatment with various digestive proteases were investigated. The most active hydrolysate was obtained with the crude protease extract from the hepatopancreas of cuttlefish (64.47 ± 1.0% at 2 mg of dry weight/ml) with a degree of hydrolysis of 8%. By gel filtration on Sephadex G-25 and RP-HPLC on C18 column, three novel peptides with high ACE-inhibitory activity were purified and their molecular masses and amino acid sequences were determined. The three peptides Val-Tyr-Ala-Pro, Val-Ile-Ile-Phe and Met-Ala-Trp with IC50 values of 6.1, 8.7 and 16.32 μM, respectively, were novel ACE-inhibitory peptides. Lineweaver-Burk plots suggest that the three purified peptides act as non-competitive inhibitors against ACE. These results suggest that some peptides from cuttlefish could be a beneficial ingredient for nutraceuticals against hypertension. © 2010 Elsevier Ltd. All rights reserved.

Badsi B.E.,University of Sfax
COMPEL - The International Journal for Computation and Mathematics in Electrical and Electronic Engineering | Year: 2013

Purpose - The aim of this paper is to propose a novel direct torque control (DTC) strategy for induction motor (IM) drives fed by three-switch three-phase inverter (TSTPI). The introduced strategy is based on the emulation of the operation of the conventional six-switch three-phase inverter (SSTPI). Design/methodology/approach - The proposed strategy has been achieved thanks to suitable combinations of the six unbalanced voltage vectors intrinsically generated by the TSTPI, leading to the synthesis of the six balanced voltage vectors of the SSTPI. This approach has been adopted in the design of the vector selection table of the proposed DTC strategy which considers a subdivision of the Clarke plane into six sectors. Findings - Simulation results have revealed that, thanks to the proposed DTC strategy, TSTPI fed IM drives exhibit interesting performance. Research limitations/implications - The results obtained by simulation should be validated by experiments. Originality/value - The drawbacks associated with the application of unbalanced voltage vectors in previous DTC strategies dedicated to TSTPI have been eradicated thanks to the synthesis of six balanced voltage vectors using appropriate combinations of the TSTPI intrinsic ones. © Emerald Group Publishing Limited.

Aguda A.H.,University of Sfax | Panwar P.,University of Sfax | Du X.,University of Sfax | Nguyen N.T.,University of Sfax | And 3 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2014

Cathepsin K is the major collagenolytic protease in bone that facilitates physiological as well as pathological bone degradation. Despite its key role in bone remodeling and for being a highly sought-after drug target for the treatment of osteoporosis, the mechanism of collagen fiber degradation by cathepsin K remained elusive. Here, we report the structure of a collagenolytically active cathepsin K protein dimer. Cathepsin K is organized into elongated C-shaped protease dimers that reveal a putative collagen-binding interface aided by glycosaminoglycans. Molecular modeling of collagen binding to the dimer indicates the participation of nonactive site amino acid residues, Q21 and Q92, in collagen unfolding. Mutations at these sites as well as perturbation of the dimer protein-protein interface completely inhibit cathepsin-K-mediated fiber degradation without affecting the hydrolysis of gelatin or synthetic peptide. Using scanning electron microscopy, we demonstrate the specific binding of cathepsin K at the edge of the fibrillar gap region of collagen fibers, which suggest initial cleavage events at the N- and C-terminal ends of tropocollagen molecules. Edman degradation analysis of collagen fiber degradation products revealed those initial cleavage sites. We propose that one cathepsin K molecule binds to collagen-bound glycosaminoglycans at the gap region and recruits a second protease molecule that provides an unfolding and cleavage mechanism for triple helical collagen. Removal of collagen-associated glycosaminoglycans prevents cathepsin K binding and subsequently fiber hydrolysis. Cathepsin K dimer and glycosaminoglycan binding sites represent novel targeting sites for the development of nonactive site-directed secondgeneration inhibitors of this important drug target.

Hmida-Sayari A.,University of Sfax | Taktek S.,University of Sfax | Elgharbi F.,University of Sfax | Bejar S.,University of Sfax
Process Biochemistry | Year: 2012

New β-1,4-d-xylan xylanohydrolase (XAn11) belonging to the xylanase 11 family was purified to homogeneity from a newly soil-isolated Aspergillus niger US368 strain. The pure xylanase is a glycosylated monomer having a molecular mass of about 26 kDa. The N-terminal sequence of the purified enzyme was determined and compared to some Aspergillus xylanases N-terminal ones. The gene encoding the XAn11 was cloned and sequenced. The maximal xylanase activity was obtained at pH 5.0 and 55 °C. The XAn11 was found to be stable in a wide range of pH (3-9) and in presence of some detergents and organic solvents. A specific activity of about 805.6 U/mg or 334 U/mg was measured using birchwood xylan or oatspelt xylan as substrate, respectively. A structural explanation of the difference between experimental and theoretical molecular mass as well as the stability of the enzyme against acidic pH was proposed by molecular modeling. © 2012 Elsevier Ltd.

Hfaiedh N.,University of Sfax | Murat J.-C.,University of Monastir | Elfeki A.,University of Sfax
Pesticide Biochemistry and Physiology | Year: 2011

The purpose of this study, carried out on male Wistar rats, was to evaluate the beneficial effects of garlic (Allium sativum) extract injections upon lindane-induced damages in testes, brain and thyroid function. Under our experimental conditions, lindane poisoning (in drinking water for 30. days, supplying about 50. mg/kg body weight per day) resulted in a decreased weight of testes, epididymides, prostate gland and seminal vesicles (-52%, -42%, -50% and -5%, respectively), a decrease of spermatozoa count and motility (-56%, -37%, respectively), an increased level of free thyroxin (+84%) and decreased levels of TSH and FSH in serum (-74%, -77%, respectively). In addition, lindane treatment triggered an oxidative stress in testes and brain as revealed by an increased level of lipids peroxidation (TBARS) (+96%,+92%), an increase of superoxide-dismutase activity in testes (+69%) and a decrease of glutathione-peroxidase and catalase activities in testes and brain (-52%, -34% and -49%, -45%, respectively). These lindane-induced changes were almost reversed to normal in animals injected with a garlic extract (an amount corresponding to 300. mg fresh garlic/kg/day), what confirms a beneficial effect of this vegetal source of anti-oxidants. © 2011 Elsevier Inc.

Soudani N.,University of Sfax
Journal of physiology and biochemistry | Year: 2011

Excess chromium (Cr) exposure is associated with various pathological conditions including hematological dysfunction. The generation of oxidative stress is one of the plausible mechanisms behind Cr-induced cellular deteriorations. The efficacy of selenium (Se) to combat Cr-induced oxidative damage in the erythrocytes of adult rats was investigated in the current study. Female Wistar rats were randomly divided into four groups of six each: group I served as controls which received standard diet, group II received in drinking water K(2)Cr(2)O(7) alone (700 ppm), group III received both K(2)Cr(2)O(7) and Se (0.5 Na(2)SeO(3) mg/kg of diet), and group IV received Se (0.5 mg/kg of diet) for 3 weeks. Rats exposed to K(2)Cr(2)O(7) showed an increase of malondialdehyde and protein carbonyl levels and a decrease of sulfhydryl content, glutathione, non-protein thiol, and vitamin C levels. A decrease of enzyme activities like catalase, glutathione peroxidase, and superoxide dismutase activities was also noted. Co-administration of Se with K(2)Cr(2)O(7) restored the parameters cited above to near-normal values. Therefore, our investigation revealed that Se was a useful element preventing K(2)Cr(2)O(7)-induced erythrocyte damages.

Aloui A.,University of Sfax | Chaouachi A.,Research Laboratory Sport Performance Optimization | Chtourou H.,Research Laboratory Sport Performance Optimization | Wong D.P.,The Hong Kong Institute of Education | And 3 more authors.
International Journal of Sports Physiology and Performance | Year: 2013

Purpose: This study examined the effects of Ramadan on cycling repeated-sprint ability (RSA) and corresponding diurnal variations. Methods: Twelve active men performed an RSA test (5 × 6-s maximal sprints interspersed with 24 s passive recovery) during morning and afternoon sessions 1 wk before Ramadan (BR), during the second (R2) and the fourth (R4) weeks of Ramadan, and 2 wk after Ramadan (AR). Maximal voluntary contraction was assessed before (MVCpre), immediately after (MVCpost), and 5 min after the RSA test (MVCpost5). Moreover, hematocrit, hemoglobin, and plasma sodium and potassium (K+) concentrations were measured at rest and after the RSA test and MVCpost. Results: Overall, peak power (Ppeak) during the RSA test decreased throughout the 5 sprints. Ppeak measured in the first sprint and MVCpre were lower during Ramadan than BR in the afternoon (P < .05) and higher in the afternoon than the morning BR and AR (P < .05). However, this diurnal rhythmicity was not found for the last 4 sprints' Ppeak, MVCpost, and MVCpost5 in all testing periods. Furthermore, the last 4 sprints' Ppeak, MVCpost, MVCpost5, and morning MVC pre were not affected by Ramadan. [K+] measured at rest and after the RSA test and MVCpost were higher during Ramadan than BR in the afternoon (P < .05) and higher in the afternoon than the morning during Ramadan (P < .05). Conclusions: Fatigability is higher in the afternoon during Ramadan, and, therefore, training and competition should be scheduled at the time of day when physical performance is less affected. © 2013 Human Kinetics, Inc.

Ben Salah C.,University of Sfax | Ouali M.,University of Sfax
Electric Power Systems Research | Year: 2011

This paper proposes two methods of maximum power point tracking using a fuzzy logic and a neural network controllers for photovoltaic systems. The two maximum power point tracking controllers receive solar radiation and photovoltaic cell temperature as inputs, and estimated the optimum duty cycle corresponding to maximum power as output. The approach is validated on a 100 Wp PVP (two parallels SM50-H panel) connected to a 24 V dc load. The new method gives a good maximum power operation of any photovoltaic array under different conditions such as changing solar radiation and PV cell temperature. From the simulation and experimental results, the fuzzy logic controller can deliver more power than the neural network controller and can give more power than other different methods in literature. © 2010 Elsevier B.V.

Masmoudi A.,University of Sfax
2013 8th International Conference and Exhibition on Ecological Vehicles and Renewable Energies, EVER 2013 | Year: 2013

The prediction of iron losses is of great importance in AC machines especially in PM brushless ones. This statement is further confirmed when dealing with fractional slot PM machines (FSPMM) since a wide speed range can be achieved. The paper is devoted to an investigation of the iron loss in both stator and rotor yoke as well as in a 12 slot/10 pole FSPMM. Based on FEA, the investigation focuses on the assessment of iron loss in the flux weakening range in so far as their increase could be a critical issue. The FEA post-processing has led to the iron loss density maps considering low and high speeds. Moreover, an analysis of the variation of the iron loss with respect to speed has been carried out. It has been found that the efficiency of the machine is greatly affected in the flux weakening range which is due to the remarkable increase of the PM eddy current loss. In order to overcome this limitation, radial segmentation of the PMs is proposed and its effect on the iron loss is analyzed. © 2013 IEEE.

Low L.-F.,Dementia Collaborative Research Center | Harrison F.,Dementia Collaborative Research Center | Harrison F.,University of Sfax | Lackersteen S.M.,Dementia Collaborative Research Center
American Journal of Geriatric Psychiatry | Year: 2013

Objective: A life course epidemiologic approach suggests that personality may have lifelong pathways of influence on risk of dementia and mild cognitive impairment (MCI). This article aimed to systematically review caseecontrol and prospective studies on the association between personality and risk of these cognitive disorders. Methods: Studies were identified through Scopus, Medline, PubMed, and PsycINFO. Searches combined terms for personality with those for dementia and MCI. Data were extracted and checked by a second reviewer, systematically reviewed, and metaanalyzed where appropriate. Results: Twelve longitudinal and three caseecontrol studies were included. Five of nine studies found that higher neuroticism was associated with greater dementia risk (pooled hazard ratio [HR] per unit increase on neuroticism score, HR = 1.13, 95% confidence interval [CI] = 1.08-1.18, z = 5.11, p <0.001, N = 3,285), and two studies showed it increased risk of MCI. Three of four studies showed that higher conscientiousness was protective against dementia (pooled HR = 0.88, 95% CI = 0.81-0.97, z = 3.34, p = 0.001, N = 1,687), and one of two studies suggested it reduced risk of MCI. Three of four studies found no association between openness and dementia; however, pooled data suggested openness was protective (HR = 0.88, 95% CI = 0.81e0.97, z = 2.34, p = 0.008, N = 1,687). Seven studies indicated that extraversion was not linked with dementia, and four found no association between agreeableness and dementia. Conclusions: Neuroticism increased risk for dementia, and conscientiousness reduced risk. The protective effect of openness was tentative. Extraversion and agreeableness were not associated with dementia. Personality should be incorporated in conceptual models of dementia risk. Clinicians and public health professionals should consider personality when planning dementia risk reduction strategies. © 2013 American Association for Geriatric Psychiatry.

Jribi S.,University of Sfax | Saha B.B.,Kyushu University | Koyama S.,Kyushu University | Bentaher H.,University of Sfax
Energy Conversion and Management | Year: 2014

In this study, a transient mathematical model of a 4-bed adsorption chiller using Maxsorb III as the adsorbent and CO2 as the refrigerant has been analyzed. The performances of the cyclic-steady-state system are presented for different heating and cooling water inlet temperatures. It is found that the desorption pressure has a big influence in the performances due to the low critical point of CO2 (Tc = 31 C). With 80 kg of Maxsorb III, the CO2 based adsorption chiller produces 2 kW of cooling power and presents a COP of 0.1, at driving heat source temperature of 95 C along with a cooling temperature of 27 C and at optimum desorption pressure of 79 bar. The present thermal compression air-conditioning system could be driven with solar energy or waste heat from internal combustion engines and therefore is suitable for both residential and mobile air-conditioning applications. © 2013 Elsevier Ltd. All rights reserved.

Hammad F.T.,University of Sfax | Kaya M.A.,Dubai Hospital
BJU International | Year: 2010

Objective To develop and validate an Arabic version of the International Prostate Symptom Score (IPSS). Patients, Subjects and Methods An Arabic version of the IPSS (IPSS-Arb) was developed through a series of translations and modifications which involved the authors, urology and non-urology medical and nursing staff. The validity and reliability were assessed in 76 patients with urinary symptoms due to benign prostatic hyperplasia (BPH) and in 63 control subjects without BPH; 25 patients had transurethral resection of prostate (TURP) whereas the remaining 51 patients were treated with terazosin. The reliability of the IPSS-Arb was assessed by determining the internal consistency (Cronbach's α coefficient) and by assessing the test-retest reliability (intraclass correlation coefficient, ICC). Construct validity was assessed by determining the correlation between the IPSS-Arb scores and the quality-of-life question (QoL-Arb), and by determining the ability of the IPSS-Arb to discriminate between the patients and controls by calculating the area under the receiver operating characteristic (ROC) curve. Results The Cronbach's α coefficient (internal consistency) for the IPSS-Arb was 0.85, and 0.78-0.88 for the individual items. The test-retest reliability (ICC) was 0.88 (P < 0.001). In addition, the IPSS-Arb had a high correlation with the QoL-Arb (Spearman rank correlation coefficient 0.82, P = 0.01). The mean (sem, 95% confidence interval) area under the ROC curve for the IPSS-Arb was 0.93 (0.09, 0.89-0.97), whereas the area for its individual questions was 0.79-0.90. The IPSS-Arb also showed a high sensitivity to change. The mean (sd) IPSS-Arb scores before and after TURP were 23.1 (6.4) and 6.9 (1.8), respectively (P < 0.001); in the terazosin group, the scores were 12.6 (7.4) and 8.2 (4.0), respectively (P < 0.001). CONCLUSIONS The IPSS-Arb was shown to be a reliable and valid instrument for patients with BPH. We recommend using it for patient assessment and follow-up, and as a research tool in Arabic-speaking patients both in the Middle East and worldwide. In addition, this study provided another proof of the wide suitability of the IPSS among various nations worldwide. © 2009 BJU INTERNATIONAL.

Dammak M.,University of Sfax | Mejdoub M.,University of Sfax | Amar C.B.,University of Sfax
VISAPP 2014 - Proceedings of the 9th International Conference on Computer Vision Theory and Applications | Year: 2014

The semantic gap is a crucial issue in the enhancement of computer vision. The user longs for retrieving images on a semantic level, but the image characterizations can only give a low-level similarity. As a result, recording a stage medium between high-level semantic concepts and low-level visual features is a stimulating task. A recent work, called Bag of visual Words (BoW) have arisen to resolve this difficulty in greater generality through the conception of techniques genius relevantly learning semantic vocabularies. In spite of its clarity and effectiveness, the building of a codebook is a critical step which is ordinarily performed by coding and pooling step. Yet, it is still difficult to build a compact codebook with shortened calculation cost. For that, several approaches try to overcome these difficulties and to improve image representation. In this paper, we introduce a survey investigates to cover the inadequacy of a full description of the most important public approaches for image categorization and retrieval. Copyright © 2014 SCITEPRESS - Science and Technology Publications. All rights reserved.

Bechor T.,Claremont Graduate University | Neumann S.,University of Sfax | Zviran M.,University of Sfax | Glezer C.,Ariel University
Information and Management | Year: 2010

Strategic information system planning (SISP) has been identified as a critical management issue. It is considered by many as the best mechanism for assuring that IT activities are congruent with those of the rest of the organization and its evolving needs. Our research investigated the success of SISP as a function of its key success factors (KSFs) in different contexts and SISP approaches, in a framework that integrated all of the SISP components and provided a new perspective on how the constructs are instrumental to produce SISP success. Based on responses from 172 American CIOs, our study's findings empirically supported our research model: the combination of SISP context and approach was found to have a moderating influence on the basic relationship between SISP KSFs and its success, the best predictor for the long-term success of the SISP process was apparently based on the three-way interactions between SISP's KSFs, its approach and its context. In addition, specific combinations of SISP approach and SISP context were found to decrease or increase the size of the "planning paradox" (the inconsistency in the behavior of the "basic relationship" between the three). © 2009 Elsevier B.V. All rights reserved.

Fourati F.,University of Sfax
14th International Conference on Sciences and Techniques of Automatic Control and Computer Engineering, STA 2013 | Year: 2013

In this paper ART2 classifier is used to extract clusters of databases taken from complex processes with different behaviors. The used classifier is an unsupervised one and the obtained clusters characterize local models of a considered system. These local models represent linear behaviors of the process. This result is the consequence of the characteristic of the F1 layer of the ART2 neural network which is divided in sublayers. © 2013 IEEE.

Ben Ayed Y.,University of Sfax
International Journal on Artificial Intelligence Tools | Year: 2015

In this paper, we propose an alternative keyword spotting method relying on confidence measures and support vector machines. Confidence measures are computed from phone information provided by a Hidden Markov Model based speech recognizer. We use three kinds of techniques, i.e., arithmetic, geometric and harmonic means to compute a confidence measure for each word. The acceptance/rejection decision of a word is based on the confidence vector processed by the SVM classifier for which we propose a new Beta kernel. The performance of the proposed SVM classifier is compared with spotting methods based on some confidence means. Experimental results presented in this paper show that the proposed SVM classifier method improves the performances of the keyword spotting system. © 2015 World Scientific Publishing Company.

Smith C.D.A.,University of Sfax | Fisher C.,University of Western Australia | Mercer A.,University of Sfax
Nursing and Health Sciences | Year: 2011

The shortage of nurses worldwide has taken its toll on the Australian healthcare system and, as a result, there is an increased migration of overseas-qualified nurses, some of them with a non-English-speaking background. Despite Australia's regulations that assess the eligibility for nursing registration, many migrant nurses who have been successful in gaining their nursing license feel only partially prepared to work. This article presents the findings of a study, based on Husserlian phenomenology, that describes the work experience of 13 female nurses who were working in Western Australia, Australia. The participants, who could recognize the core components of nursing, were taken aback by the way that nursing is practised in Western Australia. The major differences that they encountered were related to clinical skills, holistic care, the work dynamic with doctors and patients, and the overall societal status of the nursing profession. As a result, they had to adjust their practice to conform to the new work environment. In this study, the participants elaborated on some positive and some not-so-positive aspects of their experiences in their endeavor to integrate into the Western Australian metropolitan hospital setting. © 2011 Blackwell Publishing Asia Pty Ltd.

Kacem H.,University of Sfax | Bakhoum A.J.S.,University of Barcelona | Neifar L.,University of Sfax | Miquel J.,University of Barcelona
Parasitology International | Year: 2010

Spermiogenesis and the ultrastructural organization of the spermatozoon of the digenean Neoapocreadium chabaudi are described by means of transmission electron microscopy.Spermiogenesis follows the usual pattern found in the digeneans. It begins with the formation of a zone of differentiation bordered by cortical microtubules, characterized by the presence of an intercentriolar body composed of seven electron-dense plates situated between two striated rootlets and two centrioles. These centrioles give rise to two free flagella. Later, both flagella undergo a rotation of 90° and fuse with the median cytoplasmic process. Spermiogenesis finishes when the ring of arched membranes constricts. The mature spermatozoon of N. chabaudi is characterized by the presence of 2 axonemes of different lengths presenting the 9 + "1" trepaxonematan pattern, 2 bundles of parallel cortical microtubules, 2 mitochondria, a nucleus, and granules of glycogen. Nevertheless, several characters such as the morphology of sperm extremities and the presence of spinelike bodies allow us to distinguish N. chabaudi from other digenetic trematodes. The present paper provides the first ultrastructural results of a digenean belonging to the family Apocreadiidae that may be useful for the understanding of digenean relationships and phylogenetic studies. © 2010 Elsevier Ireland Ltd.

Abdi M.N.,University of Sfax | Khemakhem M.,King Abdulaziz University
Pattern Recognition | Year: 2015

Rapid movement generation models are described in the literature as an efficient tool to apprehend the handwriting behavior. Fields of application are diverse, including handwriting description, regeneration, and more recently OCR. In this paper, we propose a grapheme-based approach to offline Arabic writer identification and verification. Rather than extracting naturel graphemes from a training corpus using segmentation and clustering, it synthesizes its own graphemes based on the beta-elliptic model. Originality lies in the independence of the grapheme codebook from any training process, and the use of a model instead. One full and four partial codebooks are generated and tested. Using feature selection, raw codebooks are reduced in size with respect to FDR, FDR and cross-correlation, and random subsampling criteria. A total of 60 feature vectors are extracted using template matching, and evaluated with 411 individual writers from the IFN/ENIT database. The results presented in this study demonstrated the wide representativity and the good generalization capability of synthetic codebooks. We obtained a top1 rate=90.02% and a top5 rate=96.35% for writer identification, and an EER=2.1% for writer verification. Our approach showed better properties than most of the surveyed techniques in terms of supported corpus size and identification rates. To the best of our knowledge, this study is among the first to exploit the concept of model-based synthetic codebooks in writer identification and verification. © 2014 Elsevier Ltd. All rights reserved.

Syx E.,University of Sfax
European Journal of Health Law | Year: 2014

Although the electronic cigarette was invented in 2004, only recently the product has started to provoke discussion. On the one hand, the electronic cigarette is characterized by scientific uncertainties. It is not clear whether the device can be used in smoking cessation therapy, whether the use induces non-smokers-including minors-to start smoking and whether the vaporized substances and the act of vaporizing itself (which is smoking an electronic cigarette) is harmful. On the other hand, there is no harmonised European legal framework and different Member States attribute a different legal status to the e-cigarette. In this article, the author analyses how the e-cigarette should be qualified according to the current European legislation and ECJ case law and describes how the e-cigarette is qualified in the UK, France, the Netherlands, Belgium and Spain. © Koninklijke Brill NV, Leiden, The Netherlands.

Arif B.,University of Sfax | Ashraf J.M.,University of Sfax | Moinuddin,University of Sfax | Ahmad J.,Rajiv Gandhi Center for Diabetes and Endocrinology | And 2 more authors.
Archives of Biochemistry and Biophysics | Year: 2012

Proteins modifications in diabetes may lead to early glycation products (EGPs) as well as advanced glycation end products (AGEs). Whereas no extensive studies have been carried out to assess the role of EGPs in secondary complications of diabetes, numerous investigators have demonstrated the role of AGEs. Early glycation involves attachment of glucose on -NH2 of lysine residues of proteins leading to generation of the Amadori product (an early glycation species). This study reports the structural and immunological characterization of EGPs of HSA because we believe that during persistent hyperglycemia the HSA, one of the major blood proteins, can undergo fast glycation. Glucose mediated generation of EGPs of HSA was quantitated as Amadori products by NBT assay and authenticated by boronate affinity chromatography and LC/MS. Compared to native HSA changes in glycated-HSA were characterized by hyperchromicity, loss in fluorescence intensity and a new peak in the FTIR profile. Immunogenicity of native- and glycated-HSA was evaluated by inducing antibodies in rabbits. Results suggest generation of neo-epitopes on glycated-HSA rendering it highly immunogenic compared to native HSA. Quantization of EGPs of HSA by authentic antibodies against HSA-EGPs can be used as marker for early detection of the initiation/progression of secondary complications of diabetes. © 2012 Elsevier Inc. All rights reserved.

Massaoudi A.,SupCom | Sellami N.,University of Sfax | Siala M.,SupCom
IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC | Year: 2013

Cognitive radio is a promising technique for efficient spectrum utilization in wireless systems. In this paper, we consider an underlay cognitive radio system where a large number of secondary users (SUs) can share the spectrum with a primary user (PU). We assume that M antennas are used at the cognitive base station (CBS) and the CBS does not have the full channel state information (CSI) from secondary users. We propose to study the problem of secondary users scheduling under the assumption of imperfect CSI of the interference channel between the CBS and the primary receiver. In order to minimize the interference to the PU, we propose to generate orthogonal beams to the estimate of the channel between the CBS and the PU. Then, to reduce the amount of required feedback, we propose a scheduling algorithm based on opportunistic beamforming. To further reduce the amount of feedback, a threshold is applied to the signal to interference and noise ratio (SINR) feedback. For the proposed scheme, we develop a statistical analysis for the interference caused to the PU as well as the throughput of the secondary system. © 2013 IEEE.

Ben Ayed M.,University of Sfax | Ltifi H.,University of Sfax | Ltifi H.,University of Valenciennes and Hainaut‑Cambresis | Kolski C.,University of Valenciennes and Hainaut‑Cambresis | Alimi A.M.,University of Sfax
Decision Support Systems | Year: 2010

In this article we propose an approach for a decision support system (DSS) based on Knowledge Discovery from Databases (KDD). In such system, user must be involved throughout the decision-making process. In consequence we propose the integration of a Human-Computer Interaction (HCI) model into the development of DSS process based on KDD. The approach we propose is based on two systems development methods-the Unified Process (UP) from Software Engineering and the U model from HCI. In this article, we describe our combined approach (UP/U) and the way we used it to develop a DSS in a medical field. © 2010 Elsevier B.V. All rights reserved.

Iriarte-Goni I.,University of Sfax | Ayuda M.-I.,University of Sfax
Ecological Economics | Year: 2012

This paper analyzes wood consumption in Britain over the period 1850-1938. We calculate the apparent consumption of wood, taking into account both net imports of wood and the home harvest. We then develop some quantitative exercises that correlate wood consumption with GDP, with prices of wood and iron (as an alternative material to wood) and with other measures. The main conclusion is that, although wood had lost its economic centrality after the energy transition, wood consumption continued to grow in Britain both in absolute and relative terms, showing a positive elasticity to GDP superior to the unit. This result allows us to reach a more complete understanding of the socio-metabolic transition associated with the Industrial Revolution. Britain faced the increase in wood demand by relying almost entirely on imported wood, reinforcing the idea that the decoupling of economic growth from land use must to be handled with care, and should be observed not at the national level but on a global scale. Although British economic development was to a great extent focussed on what has been called the "subterranean forests" of coal, it simultaneously supported large tracts of surface foreign forest. © 2012 Elsevier B.V..

Cohen M.,University of Sfax | Petignat P.,University of Sfax
Cancer Letters | Year: 2011

Circulating glucose-regulated protein 78 (GRP78) autoantibodies represent potential biomarker of epithelial ovarian cancer. However there is relatively limited identification of these antibodies in response to ovarian cancer. Here, we were interested in characterization of these antibodies and into their role in tumor development. We first purified GRP78 autoantibodies from sera of patients with ovarian cancer, and then tested them on SKOV-3 ovarian cancer cell line. A decrease of invasion and an increase of H2O2-induced apoptosis of SKOV-3 cells were observed, suggesting their protective role against ovarian cancer cells. © 2011 Elsevier Ireland Ltd.

Yaakoubi M.,University of Sfax | Kchaou M.,University of Sfax | Dammak F.,University of Sfax
Computational Materials Science | Year: 2013

Simulation is a very helpful and valuable work tool in the field of heat treatment of steels. It allows behavior laws and algorithms to be learned and tested. Simulation provides a low cost, secure and fast analysis tool. For a fine assimilation of the microstructure and distortion evolution concepts which characterize the surface hardening process, a simulation of the thermo-metallurgical and mechanical coupling is elaborated by using ABAQUS software linked to phase transformation and elastic-plastic modules which we developed taking into account of interactions between these fields. The application of this method makes it possible to highlight the metallurgical and mechanical behavior laws and procedures used to calculate phase fractions, austenite grain size, hardness, microstructure effect on physical properties, transformation latent heat, deformation progress, and stress genesis during a surface hardening; which cannot be feasible by using standard software based simulation. Predicted thermo-metallurgical results and residual stress have been compared with measured ones; the coincidence between simulated and experimental values confirms the validity of the chosen simulation tool. © 2012 Elsevier B.V. All rights reserved.

Rigane A.,University of Sfax | Gourmelen C.,University of Maine, France
Journal of African Earth Sciences | Year: 2011

The present-day architecture of the Saharan Atlas in Tunisia can be defined by two principal models: (1) The first model emphasizes a general SW-NE geological structure in the North forming successive and parallel bands (the Tellian zone, the diapir zone) and the central Atlas, which are cut by the southern Atlas ranges located within a NW-SE corridor. These zones are bordered to the East by the " North-South Axis" (2) The second model defines the Tunisian Atlas in terms of an E-W strike-slip corridor, which initially controls the sedimentary facies distribution during the Meso-Cenozoïc, and which then generates elongate en echelon folds in the sedimentary cover by dextral shearing.In this study, we aim to show that the Saharan Atlas in Tunisia appears today as a triangular megablock, that we call the Tunisian Block (TB), bounded by three structural trends (N-S, SW-NE and NW-SE) belonging to the African strike-slip fault network: (1) The eastern boundary appears as a complex faulted and folded corridor limiting the folded zone of the central Atlas in the West and the depressed zone of the Sahel in the East: it corresponds to the " North-South Axis" as defined classically in the literature. (2) The southern boundary also corresponds to a faulted belt (Gafsa-Negrine-Tozeur corridor), which cuts off the continuation of the North-South axis southward into the Gabès region; it corresponds to the Southern Saharan Atlas, delimited by the Gafsa fault in the North and the Negrine-Tozeur fault in the South. (3) The northern boundary, trending SW-NE, appears rather in the form of a reverse tectonic bundle, facing SE or S (oblique convergence), whose major feature corresponds to the El Alia-Téboursouk fault. This northern boundary cuts across and delimits the N-S corridor towards the North, in such a way that its extension is limited at both extremities. Finally, the inner part of the TB actually corresponds to a mosaic of second-order blocks, each of which contains an arrangement of widely spaced SW-NE trending anticlines forming the main relief separated by vast plains very often occupied by sebkhas. The paleogeographic and structural evolution of this region during the Mesozoic and Palaeogene shows that the TB, along with its limits as defined here, developed an increasingly distinct identity at a very early stage, being characterized by an extensive and/or transtensive tectonic regime. Finally, the Tunisian Atlas Chain defines a triangular domain that owes its origin and particular character precisely because of the paleogeographic and structural history of this paleoblock. The boundaries of this paleoblock remain mobile, thus tectonically controlling the geometry and morphology of a typical intracontinental basin. The extension directions and the frequent changes of stress regime (or rotations) are related to the existence of two active basins: the strike-slip margin of the western branch of Tethys and the Mesogea oceanic basin, with tectonic activity becoming alternately dominant in one or other of the basins at different times. In this context, the Tunisian basin is characterized by rhythmic sedimentation, composed of a succession of filling sequences linked to the continuing tectonic instability of the sedimentary floor associated with two major crises: one at the end of the Aptian and the other at the end of the Ypresian. The vertical movements related to the extension and/or transtension of the blocks is accentuated by Triassic salt tectonics, giving rise to linear (salt axes) or point (salt domes) structures that lead to the formation of shoal zones during development of the basin, thus enhancing the vertical tectonics. The diapirism developed slowly and gradually from late Triassic through to Langhian times, leading to numerous sedimentary wedges on the flanks of the structures. The uprise of the diapirs exhibits three pauses corresponding to the end-Aptian, end-Ypresian and pre-Burdigalian. The vertical tectonics is characterized by abundant drape folds giving rise to an extensional fault-related folding and strike-slip/dip-slip faults creating frequent unconformities that are nevertheless always localized.Finally, the folded chain results from the structural inversion of this paleoblock from Tortonian times onward. We can only account for the various folds-axis directions in the context of an intracontinental chain where the pre-existing major vertical faults are able to develop on the surface as draped-folds in a transpressive regime by the local reorientation of stresses in crustal-scale faults. In detail, the structures produced by this vertical tectonic activity, which are profoundly controlled by inheritance, display a highly original style at very shallow levels in the crust. © 2011 Elsevier Ltd.

Khemakhem S.,University of Sfax | Amar R.B.,University of Sfax
Ceramics International | Year: 2011

Ceramic membranes can be described by an asymmetric porous material formed by a macroporous support with successive thin layers deposited on it. Paste from Tunisian silty marls referred M11, is extruded to elaborate a porous tubular configuration used as supports. The support heated at 1190 °C, shows an average pore diameter and porosity of about 9.20 μm and 49%, respectively. The elaboration of the microfiltration layer based on Tunisian clay referred JM18, is performed by slip-casting method. The heating treatment at 900 °C leads to an average pore size of 0.18 μm. The obtained membrane was surface modified to change their hydrophilic character into hydrophobic one by the grafting of the triethoxy-1H,1H,2H,2H-perfluorodecylsilane C8F 17(CH2)2Si(OC2H5) 3. The resulting products were investigated using Fourier transform infrared spectroscopy FTIR and thermogravimetric analysis TGA. The new surfaces were examined by water contact-angle measurements, Scanning Electron Microscopy (SEM) and the water fluxes through the grafted membranes were also measured. Results of the grafting of microfiltration membrane with fluoroalkylsilane will be given and discussed. The new hydrophobic membrane seems to be promising in the field of membrane distillation. High salt rejection rates higher than 99% were obtained for modified MF ceramic clay membrane. © 2011 Elsevier Ltd and Techna Group S.r.l.

Edimo W.E.,Free University of Colombia | Janssens V.,University of Sfax | Waelkens E.,University of Sfax | Erneux C.,Free University of Colombia
BioEssays | Year: 2012

Phosphoinositide (PI) phosphatases such as the SH2 domain-containing inositol 5-phosphatases 1/2 (SHIP1 and 2) are important signalling enzymes in human physiopathology. SHIP1/2 interact with a large number of immune and growth factor receptors. Tyrosine phosphorylation of SHIP1/2 has been considered to be the determining regulatory modification. However, here we present a hypothesis, based on recent key publications, highlighting the determining role of Ser/Thr phosphorylation in regulating several key properties of SHIP1/2. Since a subunit of the Ser/Thr phosphatase PP2A has been shown to interact with SHIP2, a putative mechanism for reversing SHIP2 Ser/Thr phosphorylation can be anticipated. PI phosphatases are potential target molecules in human diseases, particularly, but not exclusively, in cancer and diabetes. Therefore, this novel regulatory mechanism deserves further attention in the hunt for discovering novel or complementary therapeutic strategies. This mechanism may be more broadly involved in regulating PI signalling in the case of synaptojanin1 or the phosphatase, tensin homolog, deleted on chromosome TEN. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Saidi S.,University of Sfax | Bouri S.,University of Sfax | Ben Dhia H.,University of Sfax | Anselme B.,Paris-Sorbonne University
Agricultural Water Management | Year: 2011

Special attention has been paid to risk assessment in water resource management in arid and semi-arid regions like the Souassi aquifer, Tunisia. Risk assessment, using vulnerability and hazard mapping, is considered as a fundamental aspect of sustainable groundwater management. To determine the degree of risk affecting the study area, an attempt has been made to combine hydro-geologic parameters using the DRASTIC method and the hazard assessment by taking the product of the weighted hazard value (HI), the ranking factor (QN) and the reduction factor (Rf).All parameters used in this risk assessment were prepared, classified, weighted and integrated in a GIS environment. Data treatment shows that large areas in the Souassi aquifer can be classified as high or very high risk areas corresponding to pollution sources located in high vulnerability zones. The areas with low and very low risk are situated in the south, which could, consequently, be interesting for future development and long term planning of protective measures. Sensitivity analyses indicated that the removal of groundwater depth, net recharge and aquifer media parameters from the DRASTIC index, causes large variation in vulnerability assessment. Moreover, hydraulic conductivity and topography were found to be more effective in assessing aquifer vulnerability. Therefore, they should have higher weights than those assumed by the DRASTIC standard method, and contrary to the impact of the vadose zone parameter. The validity of the DRASTIC and the risk methods, verified by comparing the distribution of nitrates in the groundwater and the different vulnerability classes, shows a high similarity. © 2011 Elsevier B.V.

Polly P.,Inflammation and Infection Research Center | Polly P.,University of Sfax | Tan T.C.,Inflammation and Infection Research Center | Tan T.C.,Massachusetts General Hospital
Frontiers in Physiology | Year: 2014

Myopathy is a feature of many inflammatory syndromes. Chronic inflammation has been linked to pathophysiological mechanisms which implicate 1,25 dihydroxyvitamin D3 (1,25-(OH)2D3)-mediated signaling pathways with emerging evidence supporting a role for the vitamin D receptor (VDR) in contractile and metabolic function of both skeletal and cardiac muscle. Altered VDR expression in skeletal and cardiac muscle has been reported to result in significant effects on metabolism, calcium signaling and fibrosis in these tissues. Elevated levels of serum inflammatory cytokines, such as IL-6, TNF-α and IFNγ, have been shown to impact myogenic and nuclear receptor signaling pathways in cancer-induced cachexia. The dysregulation of nuclear receptors, such as VDR and RXRα in muscle cells, has also been postulated to result in myopathy via their effects on muscle structural integrity and metabolism. Future research directions include generating transcriptome-wide information incorporating VDR and its gene targets and using systems biology approaches to identify altered molecular networks in human tissues such as muscle. These approaches will aid in the development of novel therapeutic targeting strategies for inflammation-induced myopathies. © 2014 Polly and Tan.

El Badsi B.,University of Sfax | Bouzidi B.,University of Sfax | Masmoudi A.,University of Sfax
IEEE Transactions on Industrial Electronics | Year: 2013

This paper deals with a new direct torque control (DTC) strategy based on the bus-clamping technique dedicated to induction motor drives. The proposed strategy consists in the synthesis of two vector selection tables suitably arranged considering the bus-clamping technique. Such synthesis depends on the rotation direction of the stator flux vector. The resulting DTC strategy leads to clamp each motor phase during 60° interval in every half cycle of the reference stator flux vector. Therefore, a reduction of the inverter switching losses is gained. Furthermore, it has been found that the proposed DTC strategy offers a lower harmonic distortion of the motor phase currents and a higher capability to operate at low levels of the dc-bus voltage, which could be of interest for electric vehicle (EV) and hybrid electric vehicle (HEV) applications. These performances are confirmed by simulation and validated by experiments. © 2012 IEEE.

Valenzuela R.,University of Sfax | Videla L.A.,University of Chile
Food and Function | Year: 2011

Non-alcoholic fatty liver disease (NAFLD) is the most important cause of chronic liver disease that is characterized by hepatocyte triacylglycerol accumulation (steatosis), which can progress to inflammation, fibrosis, and cirrhosis (steatohepatitis). Overnutrition triggers the onset of oxidative stress in the liver due to higher availability and oxidation of fatty acids (FA), with development of hyperinsulinemia and insulin resistance (IR), and n-3 long-chain polyunsaturated FA (n-3 LCPUFA) depletion, with enhancement in the n-6/n-3 LCPUFA ratio favouring a pro-inflammatory state. These changes may lead to hepatic steatosis by different mechanisms, namely, (i) IR-dependent higher peripheral lipolysis and FA flux to the liver, (ii) n-3 LCPUFA depletion-induced changes in DNA binding activity of sterol regulatory element-binding protein 1c (SREBP-1c) and peroxisome proliferator-activated receptor α (PPAR-α) favouring lipogenesis over FA oxidation, and (iii) hyperinsulinemia-induced activation of lipogenic factor PPAR-γ. Supplementation with n-3 LCPUFA appears to reduce nutritional hepatic steatosis in adults, however, other histopathologic features of NAFLD remain to be studied. This journal is © 2011 The Royal Society of Chemistry.

Schaffer M.,Institute of Oncology | Schaffer M.,University of Oradea | Schaffer P.M.,University of Oradea | Bar-Sela G.,University of Sfax
Current Opinion in Clinical Nutrition and Metabolic Care | Year: 2015

Purpose of review Curcumin, commonly known as turmeric, is a spice that comes from the root Curcuma longa. The present article presents an update of new studies of curcumin activities as tested in anticancer models from 2011 to 2015. Recent findings Evidence from in-vitro and in-vivo research, together with clinical trials conducted over the past few decades, substantiates the potential of curcumin as an anticancer and anti-inflammatory agent. The development of formulations of curcumin in the form of nanoparticles, liposomes, micelles, or phospholipid complexes to enhance its bioavailability and efficacy are still in the early stages. Clinical trials with curcumin indicate safety, tolerability, and nontoxicity. However, the efficacy is questionable, based on the small numbers of patients in each study. Summary The laboratory and the clinical studies until 2011 were summarized in a review published in this journal. An update of the new studies and knowledge from 2011 to March 2015 focuses on new ways to overcome its low bioavailability and data from clinical trials. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.

Sakane H.,University of Sfax | Yamamoto H.,University of Sfax | Matsumoto S.,University of Sfax | Sato A.,University of Sfax | Kikuchi A.,University of Sfax
Journal of Cell Science | Year: 2012

Glypicans are members of the heparan sulfate proteoglycans (HSPGs) and are involved in various growth factor signaling mechanisms. Although HSPGs affect the β-catenin-dependent and -independent pathways of Wnt signaling, how they regulate distinct Wnt pathways is not clear. It has been suggested that the β-catenin-dependent pathway is initiated through receptor endocytosis in lipid raft microdomains and the independent pathway is activated through receptor endocytosis in non-lipid raft microdomains. Here, evidence is presented that glypican-4 (GPC4) is localized to both membrane microdomains and that the localization affects its ability to regulate distinct Wnt pathways. GPC4 bound to Wnt3a and Wnt5a, which activate the β-catenin-dependent and -independent pathways, respectively, and colocalized with Wnts on the cell surface. LRP6, one of Wnt3a coreceptors, was present in lipid raft microdomains, whereas Ror2, one of Wnt5a coreceptors, was localized to non-lipid raft microdomains. Expression of GPC4 enhanced the Wnt3a-dependent β-catenin pathway and the Wnt5a-dependent β-catenin-independent pathway, and knockdown of GPC4 suppressed both pathways. A GPC4 mutant that was localized to only non-lipid raft microdomains inhibited the β-catenin-dependent pathway but enhanced the β-catenin-independent pathway. These results suggest that GPC4 concentrates Wnt3a and Wnt5a to the vicinity of their specific receptors in different membrane microdomains, thereby regulating distinct Wnt signaling. © 2012.

De Silva V.,University of Sfax | Samarasinghe D.,University of Sfax | Hanwella R.,University of Sfax
Drug and Alcohol Review | Year: 2011

Introduction and Aims. The harm from alcohol and tobacco use in low- and middle-income countries includes substantial economic cost to the individual. Our aim was to describe the expenditure on concurrent alcohol and tobacco use in relation to family income in two districts in Sri Lanka. Design and Methods. A community-based cross-sectional study was carried out in two districts in Sri Lanka. We sampled 2684 men over 18 years of age using multistage cluster sampling. Cost of alcohol and cigarettes was calculated using the retail price for each brand and multiplying by the amount consumed. Results. Among current alcohol users 63.1% were also smokers. Among current smokers 61.9% were also using alcohol. Prevalence of concurrent alcohol and tobacco use in urban areas was 20.1% and in rural areas 14%. The two lowest income categories (<$US76 per month) spent more than 40% of their income on concurrent use while the next category ($US76-143 per month) spent 34.8% of their income on concurrent use.Discussion and Conclusions. The poor spent less than those with higher income on alcohol and tobacco, but the expenditure constituted a much larger slice of their income thus compromising their ability to meet basic needs. In low-income countries, damaging economic consequences start at lower levels of alcohol and tobacco consumption and affect a significant proportion of the population. Defining risk levels and guidelines on safe limits based purely on individual health harm has, at best, little meaning in such settings. © 2010 Australasian Professional Society on Alcohol and other Drugs.

Belguith-Hadriche O.,Laboratoire Of Biochimie | Bouaziz M.,University of Sfax | Jamoussi K.,Laboratoire Of Biochimie | Simmonds M.S.J.,Royal Botanic Gardens | And 2 more authors.
Food Chemistry | Year: 2013

The hypocholesterolemic and antioxidant activities of various extracts (water, methanol, ethyl acetate, hexane, dichloro-methane) of fenugreek seeds were investigated in cholesterol-fed rats. Only the ethyl acetate extract reduced total cholesterol, triglycerides, and low-density lipoprotein cholesterol (LDL-C) and increased high-density lipoprotein cholesterol (HDL-C) compared with those of rats fed a cholesterol-rich diet (HCD). Furthermore, the content of thiobarbituric acid-reactive substances (TBARS), and catalase and superoxide dismutase (SOD) in liver, heart and kidney decreased significantly after oral administration of the ethyl acetate extract, compared with those of HCD-fed rats. The phenolic and flavonoïd contents were highest in the methanol and the ethyl acetate extracts. These results showed that the ethyl acetate extract of the fenugreek seeds had a significant hypocholesterolemic effect and antioxidant activity in cholesterol-fed rats, whether this is partly due to the presence of flavonoïds in the extract needs further study. © 2012 Elsevier Ltd. All rights reserved.

Mirnezami R.,Imperial College London | Kinross J.M.,Imperial College London | Vorkas P.A.,University of Sfax | Goldin R.,Imperial College London | And 3 more authors.
Annals of Surgery | Year: 2012

Objective: The present review describes commonly employed metabolic profiling platforms and discusses the current and likely future application of these technologies in surgery. Background: The metabolic adaptations that occur in response to surgical illness and trauma are incompletely understood. Evaluating these will be critical to the development of personalized surgical health solutions. Metabonomics is an advancing field in systems biology, which provides a means of interrogating these metabolic shifts. Methods: Recent literature regarding metabolic profiling technologies and their applications in surgical practice are discussed. Future strategies are proposed for the incorporation of these and next-generation technologies in the evaluation of all steps in the patient surgical pathway. Results: Metabolite-based profiling has provided valuable insights into the metabolic irregularities that occur in cancer development and progression across a variety of cancer subclasses including colorectal, breast, prostate, and lung cancers. In addition, metabolic modeling has shown considerable promise in other surgical conditions including trauma and sepsis and in the assessment of pharmacotherapeutic efficacy. DISCUSSION:: Metabonomics offers a posttranscriptional view of system activity providing functional information downstream of the genome and proteome. Information at this level will provide the surgeon with a novel means of evaluating major socioeconomic problems such as cancer and sepsis. In addition, the rapid nature of emerging next generation profiling platforms provides a viable means of "real-time" perioperative metabolic assessment and optimization. © 2012 by Lippincott Williams & Wilkins.

Elfaleh N.,University of Sfax | Kamoun S.,University of Sfax
Journal of Molecular Structure | Year: 2014

The chemical preparation, the main structural, vibrational and optical features are given for a new zero dimensional alkyl tri-ammonium bismuth halogenide. (C6H20N3)BiBr6·H2O crystallize in triclinic system, space group P1¯. The crystal structure consists of discrete ionic pairs of N-(3-ammoniumpropyl)-1,3 diammoniumpropane cations, hexabromobismuthate anions and neutral water molecules linked via simple and bifurcated N-H·Br(OW) and O(W)-H·Br hydrogen bonds. Infrared and Raman spectra of (C6H20N3)BiBr6H2O were recorded at 298 K and discussed. The assignment of the observed IR and Raman lines was performed by comparison with the homologous compounds. Optical properties are investigated by optical absorption UV-visible and photoluminescence (PL) techniques. The optical absorption spectra reveal the appearance of sharp optical gaps of 3.10 eV as well as two strong green-yellow photoluminescence emissions are observed at room temperature. © 2014 Elsevier B.V. All rights reserved.

Okuwaki M.,University of Sfax | Okuwaki M.,University of Tsukuba | Okuwaki M.,Japan Science and Technology Agency | Sumi A.,University of Sfax | And 6 more authors.
Nucleic Acids Research | Year: 2012

Sperm chromatin remodeling after oocyte entry is the essential step that initiates embryogenesis. This reaction involves the removal of sperm-specific basic proteins and chromatin assembly with histones. In mammals, three nucleoplasmin/nucleophosmin (NPM) family proteinsNPM1, NPM2 and NPM3expressed in oocytes are presumed to cooperatively regulate sperm chromatin remodeling. We characterized the sperm chromatin decondensation and nucleosome assembly activities of three human NPM proteins. NPM1 and NPM2 mediated nucleosome assembly independently of other NPM proteins, whereas the function of NPM3 was largely dependent on formation of a complex with NPM1. Maximal sperm chromatin remodeling activity of NPM2 required the inhibition of its non-specific nucleic acid-binding activity by phosphorylation. Furthermore, the oligomer formation with NPM1 elicited NPM3 nucleosome assembly and sperm chromatin decondensation activity. NPM3 also suppressed the RNA-binding activity of NPM1, which enhanced the nucleoplasmnucleolus shuttling of NPM1 in somatic cell nuclei. Our results proposed a novel mechanism whereby three NPM proteins cooperatively regulate chromatin disassembly and assembly in the early embryo and in somatic cells. © 2012 The Author(s).

Posma J.M.,University of Sfax | Robinette S.L.,University of Sfax | Holmes E.,University of Sfax | Nicholson J.K.,University of Sfax
Bioinformatics | Year: 2014

Summary: MetaboNetworks is a tool to create custom sub-networks in Matlab using main reaction pairs as defined by the Kyoto Encyclopaedia of Genes and Genomes and can be used to explore transgenomic interactions, for example mammalian and bacterial associations. It calculates the shortest path between a set of metabolites (e.g. biomarkers from a metabonomic study) and plots the connectivity between metabolites as links in a network graph. The resulting graph can be edited and explored interactively. Furthermore, nodes and edges in the graph are linked to the Kyoto Encyclopaedia of Genes and Genomes compound and reaction pair web pages. © 2013 The Author 2013. Published by Oxford University Press.

Jeddi K.,University of Sfax | Chaieb M.,University of Sfax
Flora: Morphology, Distribution, Functional Ecology of Plants | Year: 2010

In this study, characteristics of vegetation and soil properties under continued grazing and exclusion of livestock for 6 and 12 years were examined in a degraded Stipa tenacissima steppe in South Tunisia. Exclosures enhance the total plant cover, the dry matter yield, the number of species per unit area and the Shannon-Wiener diversity. Some palatable species were frequently found inside the protected site. In the continually grazed site, these species are being replaced by less desirable species. Contents of soil organic matter, total nitrogen, Ca2+ and K+ in soils, as well as, water infiltration rate and basal soil respiration showed an increasing trend as time of grazing exclusion increased, from minimum values in the continually grazed area (Gr) to the maximum levels in 12 years protected area (12ex), while there was an opposite trend for Na+ concentration, EC, pH and soil hydrophobicity values. The results suggested that excluding grazing livestock on the arid degraded steppes has a great potential to restore vegetation and soil. Therefore, it must be encouraged as an alternative to stop further degradation and to combat desertification in arid and semi arid ecosystems. © 2009 Elsevier GmbH. All rights reserved.

Jeddi K.,University of Sfax | Chaieb M.,University of Sfax
Land Degradation and Development | Year: 2010

In arid and semiarid Mediterranean areas, Pinus halepensis Mill. is one of the dominant forest species and is widely used in restoration programmes. We collected samples and investigated the understory plant species in an age sequence of 0-, 5-, 9-, and 13-year-old P. halepensis plantations to assess the effect of the tree on soil properties and development of plant community. Soil samples were taken from two depths (-10 and 10-30cm) under tree canopy and in the associated open spaces. Results showed that tree establishment and development enhanced organic C, total N, and available P accumulation, and improved soil moisture content which increased significantly with increasing plantation age. At the same time, P. halepensis facilitated the colonization and development of understory vegetation. Indeed, the number of plant species, the total plant cover, and the perennial species density were more important under tree canopy and increased with increasing plantation age. The soil dynamic under 13-year-old P. halepensis plantations reflected two phase restoration sequence, characterized by nominal changes during tree establishment (0-5 years) and marked and rapid changes associated with the start of canopy closure (5-13 years). Our results provide that the introduction of P. halepensis with afforestation could be an effective and applicable measure to restore arid degraded areas. Copyright © 2010 John Wiley & Sons, Ltd.

Dangsuwan P.,University of Sfax | Manchana T.,University of Sfax
Gynecologic Oncology | Year: 2010

Objective: To compare the incidence of repeated red blood cell (RBC) transfusion in anemic gynecologic cancer patients receiving platinum-based chemotherapy comparing intravenous and oral iron. Materials and methods: Forty-four anemic gynecologic cancer patients (hemoglobin level below 10 mg/dl) who required RBC transfusion were stratified and randomized according to baseline hemoglobin levels and chemotherapy regimen. Study group received 200 mg of intravenous iron sucrose and control group received oral ferrous sulphate 600 mg/day. RBC transfusion requirement in the consecutive cycle of chemotherapy was the primary outcome. Quality of life was evaluated by validated Thai version of the Functional Assessment of Cancer Therapy-Anemia (FACT-An). Results: In a total of the 44 patients, there were 22 patients in each group. Five patients (22.7%) in the study group and 14 patients (63.6%) in the control group required RBC transfusion in consecutive cycle of chemotherapy (p = 0.01). No significant difference in baseline hemoglobin and hematocrit levels was demonstrated in both groups. Significantly higher mean hemoglobin and hematocrit levels after treatment were reported in the study group (10.0 ± 0.8 g/dl and 30.5 ± 2.4%) than the control group (9.5 ± 0.9 g/dl and 28.4 ± 2.7%). No significant change of total FACT-An scores was noted between before and after treatment in both groups. No serious adverse events were reported and there was no significant difference among adverse events between both groups. Conclusion: Intravenous iron is an alternative treatment for anemic gynecologic cancer patients receiving platinum-based chemotherapy and reduces the incidence of RBC transfusion without serious adverse events. © 2009 Elsevier Inc. All rights reserved.

Hawkins C.L.,University of Sfax | Davies M.J.,Heart Research Institute
Biochimica et Biophysica Acta - General Subjects | Year: 2014

Background: Electron paramagnetic resonance (EPR) spectroscopy (also known as electron spin resonance, ESR, spectroscopy) is widely considered to be the "gold standard" for the detection and characterisation of radicals in biological systems. Scope of review: The article reviews the major positive and negative aspects of EPR spectroscopy and discusses how this technique and associated methodologies can be used to maximise useful information, and minimise artefacts, when used in biological studies. Consideration is given to the direct detection of radicals (at both ambient and low temperature), the use of spin trapping and spin scavenging (e.g. reaction with hydroxylamines), the detection of nitric oxide and the detection and quantification of some transition metal ions (particularly iron and copper) and their environment. Major conclusions: When used with care this technique can provide a wealth of valuable information on the presence of radicals and some transition metal ions in biological systems. It can provide definitive information on the identity of the species present and also information on their concentration, structure, mobility and interactions. It is however a technique that has major limitations and the user needs to understand the various pitfalls and shortcoming of the method to avoid making errors. General significance: EPR remains the most definitive method of identifying radicals in complex systems and is also a valuable method of examining radical kinetics, concentrations and structure. This article is part of a Special Issue entitled Current methods to study reactive oxygen species - pros and cons and biophysics of membrane proteins. Guest Editor: Christine Winterbourn. © 2013 Elsevier B.V. All rights reserved.

De Silva V.A.,University of Sfax | Hanwella R.,University of Sfax
International Clinical Psychopharmacology | Year: 2012

Specific serotonin reuptake inhibitors (SSRIs) are considered as first-line treatment in major depressive disorder (MDD). There is evidence that venlafaxine may be more effective than several antidepressants in the treatment of MDD. This meta-analysis includes all published, randomized, double-blind, head-to-head trials, which compared venlafaxine and an SSRI in the treatment of MDD in adults. Twenty-six trials comparing venlafaxine with an SSRI were included (total participants: 5858). Meta-analysis using a random effect model showed that venlafaxine was superior to SSRIs in achieving remission [odds ratio (OR)=1.13, 95% confidence interval (CI)=1.0-1.28, P=0.05] and response (OR=1.17, 95% CI=1.03-1.34, P=0.02). Subgroup analysis found that venlafaxine had a significantly better response rate than fluoxetine (OR=1.28, 95% CI=1.05-1.55, P=0.01). There were no significant differences in response or remission between venlafaxine and other individual SSRIs. There was no significant difference in all cause discontinuation between venlafaxine and SSRIs (OR=1.10, 95% CI=0.97-1.25, P=0.15). Venlafaxine had significantly higher discontinuation due to adverse events compared with SSRIs (OR=1.41, 95% CI=1.10-1.79, P=0.006). The superior efficacy of venlafaxine over SSRIs is of clinical importance. However, higher rates of discontinuation due to adverse events for venlafaxine compared with SSRIs are a disadvantage. Findings of this meta-analysis that included only published studies were similar to those from meta-analysis that included unpublished data. © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Andres P.,University of Sfax
Computational Statistics and Data Analysis | Year: 2014

Recently, the Dynamic Conditional Score (DCS) or Generalized Autoregressive Score (GAS) time series models have attracted considerable attention. This motivates the need for a software package to estimate and evaluate these new models. A straightforward to operate program called the Dynamic Score (DySco) package is introduced for estimating models for positive variables, in which the location/scale evolves over time. Its capabilities are demonstrated using a financial application. © 2014 The Author. Published by Elsevier B.V.

Guo M.,University of Sfax
Infectious Diseases in Clinical Practice | Year: 2015

ABSTRACT: Bartonella quintana infection is commonly associated with alcohol abuse and homelessness and can be a cause of blood culture-negative infective endocarditis. Bartonella endocarditis has a subacute clinical course and can cause severe valvular disruption with potentially fatal outcomes. Its diagnosis requires a high index of suspicion in the clinical scenario of culture-negative endocarditis and may require serological testing, western blotting, or culture in specialized media. 16S RNA amplification sequencing analysis and histopathological examination may be helpful if a surgical specimen is available. We present a case of blood culture-negative infective endocarditis in the context of active pulmonary tuberculosis; endocarditis caused by Mycobacteria tuberculosis is extremely rare so another cause of the endocarditis was sought. Bartonella quintana was confirmed as the cause by molecular detection done on the vegetation. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.

Masmoudi M.,University of Sfax | Rahal C.,University of Sfax | Abdelmouleh M.,University of Sfax | Abdelhedi R.,University of Sfax
Applied Surface Science | Year: 2013

In this paper, we have studied the hydrolysis process of γ-aminopropyltriethoxysilane (γ-APS) at ethanol-water solution by means of Fourier-transform infrared spectroscopy (FTIR and DRIFT). Films of γ-APS with different hydrolysis time are formed on copper surface. 2 h is chosen as the best hydrolysis time of γ-APS in ethanol water solution. We have also investigated the chemisorbed γ-APS film onto copper surface at different dried conditions. We have used DRIFT and contact angle techniques to characterize the formed films. Curing or aging curing treatment leads to additional polymerization, better interconnected networks, increase in the silane quality and/or more robust silane layer and more hydrophilic copper surface. © 2013 Published by Elsevier B.V.

Boudhiaf R.,University of Sfax | Baccar M.,University of Sfax
Energy Conversion and Management | Year: 2014

The impoverishment of our planet in non-renewable energies has incited researchers to design salinity gradient solar ponds to collect and store solar energy at a lower cost. It is in this context that the present research work lies to focus on the numerical study of the transient hydrodynamic, heat and mass transfer in a salinity gradient solar pond. The problem is tackled using the dimensionless governing equations of Navier-Stokes, thermal energy and mass transfer, which are solved numerically by finite-volume method to provide the temperature, concentration and velocity fields in transient regime. The pond is filled with salty water of various salinities to form three zones of salty water: Upper Convective Zone (UCZ), Non-Convective Zone (NCZ) and Lower Convective Zone (LCZ). To prevent convective movements induced by the internal heating of salty water due to solar radiation absorption, a salinity gradient is used in the solar pond. Representative results illustrating the influence of internal Rayleigh number on the thermal performance of the pond and the effect of the aspect ratio on the distribution of temperature and velocity fields in the salinity gradient solar pond (SGSP) are discussed. In addition, results for the transient average temperature of UCZ and LCZ are presented and discussed for various parametric conditions. © 2014 Elsevier Ltd. All rights reserved.

Lourdault K.,Institute Pasteur Paris | Cerqueira G.M.,Institute Pasteur Paris | Cerqueira G.M.,University of Sfax | Wunder E.A.,Oswaldo Cruz Foundation | And 2 more authors.
Infection and Immunity | Year: 2011

Leptospira interrogans is the causative agent of leptospirosis, which is an emerging zoonotic disease. Resistance to stress conditions is largely uncharacterized for this bacterium. We therefore decided to analyze a clpB mutant that we obtained by random transposon mutagenesis. The mutant did not produce any of the two isoforms of ClpB. The clpB mutant exhibited growth defects at 30° and 37°C and in poor nutrient medium and showed increased susceptibility to oxidative stress, whereas the genetically complemented strain was restored in ClpB expression and in vitro wild-type growth. We also showed that the clpB mutant was attenuated in virulence in an animal model of acute leptospirosis. Our findings demonstrate that ClpB is involved in the general stress response. The chaperone is also necessary, either directly or indirectly, for the virulence of the pathogen L. interrogans. © 2011, American Society for Microbiology.

Ben Mabrouk A.,University of Sfax | Ferraria A.M.,University of Lisbon | Botelho do Rego A.M.,University of Lisbon | Boufi S.,University of Sfax
Cellulose | Year: 2013

Efficient surface functionalization of cellulose nanocrystals (CNC) with hydroxyl butyl acrylate monomer (HBA) was carried on under mild condition using N,N′-carbonyldiimidazole as an activator. The grafting of the acrylic monomer was shown to bring about the high yield grafting of polymer chains on the functionalized CNC during in situ polymerization process. Surface functionalization of CNC with HBA and the polymer grafting on the modified CNC were confirmed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Nanocomposite film prepared from in situ polybutylmethacrylate polymerization process using HBA functionalized nanocrystals exhibited high transparency degree here assigned to improved dispersion. DMA analysis proved that the best mechanical/rheological performance is obtained for HBA-CNC contents of 4 %. © 2013 Springer Science+Business Media Dordrecht.

Adams S.,University of Sfax | Adams S.,St Vincents Hospital | Braidy N.,University of New South Wales | Bessesde A.,University of New South Wales | And 7 more authors.
Cancer Research | Year: 2012

Brain tumors are among the most common and most chemoresistant tumors. Despite treatment with aggressive treatment strategies, the prognosis for patients harboring malignant gliomas remains dismal. The kynurenine pathway (KP) is the principal route of L-tryptophan catabolism leading to the formation of the essential pyridine nucleotide, nicotinamide adenine dinucleotide (NAD +), and important neuroactive metabolites, including the neurotoxin, quinolinic acid (QUIN), the neuroprotective agent, picolinic acid (PIC), the TH17/Treg balance modulator, 3-hydroxyanthranilic acid (3-HAA), and the immunosuppressive agent, L-Kynurenine (KYN). This review provides a new perspective on KP dysregulation in defeating antitumor immune responses, specifically bringing light to the lower segment of the KP, particularly QUIN-induced neurotoxicity and downregulation of the enzyme α-amino- β-carboxymuconate-ε-semialdehyde decarboxylase (ACMSD) as a potential mechanism of tumor progression. Given its immunosuppressive effects, 3-HAA produced from the KP may also play a role in suppressing antitumor immunity in human tumors. The enzyme indoleamine 2, 3-dioxygenase (IDO-1) initiates and regulates the first step of the KP in most cells. Mounting evidence directly implicates that the induction and overexpression of IDO-1 in various tumors is a crucial mechanism facilitating tumor immune evasion and persistence. Tryptophan 2, 3-dioxygenase (TDO-2), which initiates the same first step of the KP as IDO-1, has likewise recently been shown to be a mechanism of tumoral immune resistance. Further, it was also recently shown that TDO-2-dependent production of KYN by brain tumors might be a novel mechanism for suppressing antitumor immunity and supporting tumor growth through the activation of the Aryl hydrocarbon receptor (AhR). This newly identified TDO-2-KYN-AhR signaling pathway opens up exciting future research opportunities and may represent a novel therapeutic target in cancer therapy. Our discussion points to a number of KP components, namely TDO-2, IDO-1, and ACMSD, as important therapeutic targets for the treatment of brain cancer. Targeting the KP in brain tumors may represent a viable strategy likely to prevent QUIN-induced neurotoxicity and KYN and 3-HAA-mediated immune suppression. ©2012 AACR.

Abdelrazik A.M.,University of Sfax | Elshafie S.M.,University of Sfax | Ezzat Ahmed G.M.,University of Sfax | Abdelaziz H.M.,University of Sfax
Transfusion | Year: 2013

BACKGROUND: Rh discrepancies are a problem during routine testing because of partial and weak D phenotypes. Some blood units with weak and partial D expression may escape detection by serology. Limitations of serology can be overcome by molecular typing. The objective of study was to compare currently used serologic methods with molecular analysis to determine the potential application of molecular methods to improve D typing strategies and to estimate the frequency of weak D types among the Arab population. STUDY DESIGN AND METHODS: Fifty blood donor and patient samples with discrepant results of D phenotyping were subjected to routine serology to define the D phenotype including monoclonal anti-D immunoglobulin M and indirect antiglobulin test. Commercially available panels of monoclonal anti-D were used for identification of partial D and weak D phenotypes. Genomic DNA was evaluated using allele-specific amplification polymerase chain reaction with sequencespecific primers to define weak D type. RESULTS: Molecular typing confirmed most of the serology results; three samples that were not clear-cut serologically were identified by molecular typing, two samples as weak D Type 4.2 (DAR), and one sample as weak D Type 4.0. Another two samples identified by serologic panel as weak D were unresolved by molecular typing. A sample with partial D Type II by serology revealed a Weak D Type 4.0 by molecular typing. Results interestingly showed the high frequency of weak D Type 4.2 (DAR) in Egypt. CONCLUSION: RHD molecular typing can solve discrepancies during routine testing due to partial and weak D phenotypes for better transfusion outcome.

Naumkin F.Y.,University of Sfax | Wales D.J.,University of Cambridge
Chemical Physics Letters | Year: 2016

Structure, stability and electronic properties are evaluated computationally for small Ben (n = 5–9) cluster cages accommodating atomic H inside and forming core-shell species. These parameters are predicted to vary significantly upon insertion of H, for ionic derivatives, and with the system size. In particular, the energy barrier for H-atom exit from the cage changes significantly for ions compared to the neutral counterparts. The corresponding effects predicted for cage assemblies suggest the possibility of efficient charge-control of hydrogen release. This, together with a high capacity for storing hydrogen in extended such assemblies might indicate a possible way towards feasible hydrogen-storage solutions. © 2016 Elsevier B.V.

Turki H.,University of Sfax
Journal of Materials and Environmental Science | Year: 2016

In this research paper, a ranking of the 61 main Tunisian scientists in chemistry and materials science working in Tunisia and abroad is provided. It is clearly seen that 37 out of 61 scientists are working in Tunisia and this is explained by the tendency of Tunisian universities having to work on interdisciplinary research that is known for providing more citations than theoretical and applied research. However, the performance of the Tunisian main scientists working abroad appears superior to the one of the local Tunisian main scientists. This is explained by the better conditions of research offered outside Tunisia and maybe by a deficiency in their choice of international collaboration. A new policy should then be elaborated to improve the organization of such research collaborations and let them more fructuous.

Noumi Z.,University of Sfax | Chaieb M.,University of Sfax
Acta Botanica Gallica | Year: 2012

Acacia tortilis subsp. raddiana is one of the most uncommon species and is still present in North African regions. Indeed, the region of Bled Talah, in the south of Tunisia, constitutes today an ecosystem where the species continues to grow on a large surface of 16,488 ha. There is little information on the long-term dynamics of Acacia trees. The overall objectives of this study are to know the total individuals of Acacia trees which help to assess the density, to study the structure of Acacia population, to estimate the age of Acacia population and to determine the effects of A. tortilis canopy on soil properties. In this context, all individuals of A. tortilis covering 5,114 ha in the National Park Bov Hedma, were systematically counted. Many dendrometric parameters were measured. In our study, age determination of A. tortilis is based on the counting of rings. Our results show that the population of A. tortilis subsp. raddiana in the region of Bou Hedma is characterised by an irregular structure, involved in a regressive dynamic. They show also that A. tortilis trees improve soil water availability and the nutrient status of soil. Copyright © 2012 Société botanique de France.

Ktari N.,University of Sfax | Jridi M.,University of Sfax | Bkhairia I.,University of Sfax | Sayari N.,University of Sfax | Nasri M.,University of Sfax
Food Research International | Year: 2012

The objective of this work was to evaluate the composition, functional properties and in vitro antioxidative activities of zebra blenny (Salaria basilisca) protein hydrolysates prepared using crude alkaline protease extracts from zebra blenny, sardinelle and smooth hound viscera. Zebra protein hydrolysates (ZPHs) obtained by treatment with crude enzyme from the same species (ZPH-Z), crude enzyme from sardinelle (ZPH-S) and crude enzyme from smooth hound (ZPH-SH) contained high protein content 85.77%, 85.51% and 85.2%, respectively. All protein hydrolysates had an excellent solubility and possessed interfacial properties, which were governed by their concentrations. The antioxidant activities of ZPHs were evaluated using various in vitro antioxidant assays: 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, reducing power, ferrous chelating activity, hydroxyl radical-scavenging activity and DNA nicking assay. All hydrolysates showed varying degrees of antioxidant activity and almost the same strongest protection against hydroxyl radical induced DNA breakage. © 2012 Elsevier Ltd.

Hammad F.T.,University of Sfax | Balakrishnan A.,Dubai Hospital
Journal of Endourology | Year: 2010

Background: Few studies have addressed the effect of skin-to-stone distance (SSD) on the success of extracorporeal shockwave lithotripsy (SWL). Nevertheless, the effect of the two components of SSD, that is, the fat SSD (FSSD) and nonfat SSD (NFSSD) components, was not previously investigated. Methods: In this prospective study, all patients (n=113) who had single radio-opaque kidney stones and underwent SWL for the first time between January 2006 and June 2007 were recruited. SSD, FSSD, and NFSSD were measured by noncontrast CT scan at 0°, 45°, and 90° and the average was calculated. The outcome was defined as successful (completely stone free or residual fragments ≤3mm) or unsuccessful (residual fragments >3mm or complete failure of fragmentation). Results: Sixty-nine (61%) patients had successful treatment. On univariate analysis, SSD, FSSD, and NFSSD were significantly lower in the successful group compared with those with unsuccessful outcome (71.9±13.3 vs. 86.2±25.1mm [p=0.001], 27.2±10.3 vs. 36.1±17.3mm [p=0.011], and 44.7±7.2 vs. 50.1±13.9mm [p=0.02], respectively). The muscle component of the NFSSD was also lower in the successful group (21.5±4.1 vs. 25.2±10.0mm [p=0.01]). On multivariate analysis, factors that independently predicted treatment success were SSD, stone attenuation, and stone size but not the FSSD or NFSSD. Conclusions: Although the total SSD appeared to be a significant predictor of SWL success, its fat and nonfat components did not independently predict the final outcome and only appeared to be important through their contribution to the total SSD. Copyright 2010, Mary Ann Liebert, Inc.

Saibi W.,University of Sfax | Gargouri A.,University of Sfax
Journal of Molecular Catalysis B: Enzymatic | Year: 2011

Stachybotrys microspora is a filamentous fungus secreting various β-glucosidases. The current work undertakes purification and biochemical characterization of the most particular one, named bglG, which is the only one to be highly produced on glucose and fairly on cellulose-based medium. Although produced on glucose, bglG activity continues to be highly inhibited by this sugar. After two chromatographic steps, bglG was purified to homogeneity and shown to be a monomeric protein with the molecular mass of 225 kDa. The highest bglG activity was obtained at pH 5 and a temperature range of 50-60 °C. This enzyme was shown to act through a retaining-enzyme mechanism. The N-terminal sequence analysis did not reveal any homology with all available sequences in the database. BglG is somehow atypical for multiple reasons: (1) BglG is insensitive to the conventional Coomassie staining protocol and CuCl2 method was applied to reveal the protein; (2) the bglG activity is strongly enhanced by ferrous ion (Fe2+) to 161% at 5 and 10 mM of Fe 2+. Flame spectrometry analysis showed that iron was stoechiometrically and strongly bound to bglG; (3) besides cellobiose, BglG is active on sucrose (114%); a rarely described property among β-glucosidases and (4) bglG is significantly stimulated by xylose. BglG could be considered as very original, since all known β-glucosidases, did not share these properties. © 2011 Elsevier B.V.

Zohra B.S.,University of Sfax | Habib A.,University of Sfax
Environmental Science and Pollution Research | Year: 2016

Contamination of heavy metals in sediment is regarded as a global crisis with a large share in industrializing cities like Sfax (Tunisia). Seven heavy metals such as Cadmium (Cd), Copper (Cu), Iron (Fe), Mercury (Hg), Nickel (Ni), Lead (Pb), and Zinc (Zn), and one metalloid such as Arsenic (As) in sediments and fish (D. annularis, L. aurata, and S. vulgaris) were investigated from the Southern coast of Sfax in Tunisia. The range of metals in sediments were 13.11–36; 4.42–7.92; 8.23–28.56; 50,564–11,956; 2.9–6.8; 9.13–30.51; 65.06–151.50, and 47–546 kg−1 DW for As, Cd, Cu, Fe, Hg, Ni, Pb, and Zn. The level of studied metals in sediment samples exceeded the limits of the quality assessment guidelines (SQGs). The potential ecological risk index (PERI) proved that the investigated region could pose moderate risk for the aquatic biota. Metal bioaccumulation in the fish muscles varied significantly among species. Indeed, S. vulgaris and D. annularis accumulated higher amount of metal than L. aurata. The target hazard quotients (THQ) of individual heavy metals in fish, except for As and Hg, revealed safe levels for human consumption. Nevertheless, the total THQ indexes exceeded 1 suggesting the combined effects on muscles fish, which may constitute a risk to population’s health. © 2016 Springer-Verlag Berlin Heidelberg

Ammar F.,University of Sfax | Makhlouf A.,Upper Alsace University | Silvestrov S.,Lund University
Journal of Physics A: Mathematical and Theoretical | Year: 2010

In this paper we construct ternary q-Virasoro-Witt algebras which q-deform the ternary Virasoro-Witt algebras constructed by Curtright, Fairlie and Zachos using su(1, 1) enveloping algebra techniques. The ternary Virasoro-Witt algebras constructed by Curtright, Fairlie and Zachos depend on a parameter and are not Nambu-Lie algebras for all but finitely many values of this parameter. For the parameter values for which the ternary Virasoro-Witt algebras are Nambu-Lie, the corresponding ternary q-Virasoro-Witt algebras constructed in this paper are also Hom-Nambu-Lie because they are obtained from the ternary Nambu-Lie algebras using the composition method. For other parameter values this composition method does not yield a Hom-Nambu-Lie algebra structure for q-Virasoro-Witt algebras. We show however, using a different construction, that the ternary Virasoro-Witt algebras of Curtright, Fairlie and Zachos, as well as the general ternary q-Virasoro-Witt algebras we construct, carry a structure of the ternary Hom-Nambu-Lie algebra for all values of the involved parameters. © 2010 IOP Publishing Ltd.

Mnif I.,University of Sfax | Elleuch M.,University of Sfax | Chaabouni S.E.,University of Sfax | Ghribi D.,University of Sfax
Crop Protection | Year: 2013

Bacillus subtilis SPB1 was shown to produce a lipopeptide biosurfactant. The insecticidal activity of this biosurfactant was evaluated against Ectomyelois ceratoniae Zeller, a moth pest of stored dates in Tunisia. The LC50 and LC90 values after six days of contact were 152μg/g and 641μg/g, respectively. To promote an economical production of this highly effective bioinsecticide, statistical experimental designs and response surface methodology were employed to optimize the concentrations of agro-industrial residues and humidity, for lipopeptide biosurfactant production by B.subtilis SPB1 under solid state fermentation. The optimal medium leading to a production yield near to 28mg of crude lipopeptide preparation per g of wet solid material was composed of a mixture of 4.34g of tuna fish flour and 5.66g of potato waste flour with a moisture content of 76%. © 2013 Elsevier Ltd.

Peach G.,University of Sfax | Kim C.,Imperial College London | Zacharakis E.,University of Sfax | Purkayastha S.,University of Sfax | Ziprin P.,University of Sfax
British Journal of Cancer | Year: 2010

Background:The role of adjuvant chemotherapy after resection of colorectal cancers (CRCs) is well understood for patients with stage-I or stage-III disease. Its efficacy for those with stage-II disease remains much less clear. Many investigators have sought to identify prognostic markers that might clarify which patients have the highest risk of recurrence and would, therefore, be most likely to benefit from chemotherapy. This systematic review examines evidence for the use of peripherally sampled, circulating tumour cells (CTCs) as such a prognostic marker.Methods:A comprehensive literature search was used to identify studies reporting on the significance of CTCs in the postoperative blood of CRC patients.Results:Fourteen studies satisfied the inclusion criteria. Six of the nine studies that took blood samples 24 h or more postoperatively found detection of postoperative CTCs to be an independent predictor of cancer recurrence.Conclusion:The presence of CTCs in peripheral blood at least 24 h after resection of CRCs is an independent prognostic marker of recurrence. Further studies are needed to clarify the optimal time point for blood sampling and determine the benefit of chemotherapy in CTC-positive patients with stage-II disease. © 2010 Cancer Research UK All rights reserved.

Ben-Ayed R.,University of Sfax | Kamoun-Grati N.,University of Sfax
Comprehensive Reviews in Food Science and Food Safety | Year: 2013

Adulteration of virgin olive oil with less expensive oils is a serious problem for the public and quality control evaluators of olive oil. That is why olive oil authenticity has become a major issue for producers, consumers, and policy makers. In order to avoid fraud to consumers, it is crucial to study the traceability of olive oil. This review covers 2 important techniques, analytical, and molecular methods, used to characterize olive oil and detect possible adulteration. Several analytical techniques are discussed for the detection of olive oil adulteration by analyzing minor and major compounds of olive oil. However, the chemical composition of olive oil can dramatically change due to the environmental and processing conditions. For this reason, the DNA-based technologies are gaining greater attention now because they are not influenced by environmental conditions and provide an opportunity for direct comparison of different genetic materials. In this review, we emphasize the great potential of different authenticity methods and discuss their practical implementation in olive oil traceability. © 2013 Institute of Food Technologists®.

Zarai Z.,University of Sfax | Boujelbene E.,University of Sfax | Ben Salem N.,University of Sfax | Gargouri Y.,University of Sfax | Sayari A.,University of Sfax
LWT - Food Science and Technology | Year: 2013

Black pepper (Piper nigrum L.) has long been regarded as a spice added to many foods and it is also considered as a medicinal plant. The predominant compound obtained from ethanolic extract of P. nigrum, the piperine, was purified and identified by HPLC, 13C NMR and by FT-IR analysis. Piperic acid was synthesized by alkaline hydrolysis of the purified piperine. The antioxidant and the antibacterial activities of different solvent extracts from P. nigrum and purified piperine and piperic acid were determined by using various in vitro tests. In all ours experiments, synthesized piperic acid was found to have the highest antioxidant power and was the most effective with the minimum inhibitory concentration (<325 μg/ml) against all strains tested. This comparative report indicates that these compounds, piperine and piperic acid, could be used as natural antioxidant and antibacterial agents in both food preservation and human health. © 2012 Elsevier Ltd.

Affes H.,University of Sfax
Journal of Internet Banking and Commerce | Year: 2016

In this study, our plan is to examine the relationship between the history (perceived support, open communication, cultural sensitivity) and the dimensions of the quality of the franchiser-franchisee relationship (trust, commitment, satisfaction). We started by studying this relationship in a context of franchisees’ normative expectations. Our methodological approach consists in conducting a survey with 124 franchisees in the Tunisian context. The achieved results revealed that the three patterns of the tested model, and mainly the perceived support and open communication, strongly contribute to the consolidation of the quality of the franchise relationship. Moreover, it was shown that part of the effect of each pattern on the assessment of the relationship quality is explained by the validation of the franchisees’ normative expectations. © Ghodbane Adel, 2016.

Zhani K.,University of Sfax | Ben Bacha H.,University of Sfax | Ben Bacha H.,P.A. College | Damak T.,University of Sfax
Energy | Year: 2011

This paper presents the modeling and the experimental validation of air and water solar collectors used in humidification-dehumidification (HDH) solar desalination unit. The solar desalination process is currently operating under the climatological conditions of Sfax (34 N, 10 E), Tunisia. To numerically simulate the air and water solar collectors, we have developed dynamic mathematical models of the solar collectors. The resulting distributed parametric systems of equations are transformed into a system of ordinary differential equations (ODEs) using the orthogonal collocation method (OCM). A comparison between numerical and experimental data was conducted. It was found that the two-temperature mathematical model describes more precisely the real behaviour of the water solar collector than the one-temperature mathematical model. It was also shown that the developed mathematical models are able to predict accurately the trends of the thermal characteristic of the water and air solar collectors. As a result, the proposed models can be used to size and test the behaviour of such a type of water and air solar collectors. © 2011 Elsevier Ltd.

Cragg J.J.,University of Sfax | Noonan V.K.,Rick Hansen Institute | Krassioukov A.,International Collaboration on Repair Discoveries ICORD | Krassioukov A.,Strong Rehabilitation Center | And 3 more authors.
Neurology | Year: 2013

Objective: To evaluate the association between cardiovascular disease (CVD) and spinal cord injury (SCI) in a large representative sample. Methods: Data were compiled from more than 60,000 individuals from the 2010 cycle of the cross-sectional Canadian Community Health Survey (CCHS). Multivariable logistic regression analysis was conducted to examine this relationship, adjusting for confounders and using probability weighting to account for the CCHS sampling method. Results: After adjusting for age and sex, SCI was associated with a significant increased odds of heart disease (adjusted odds ratio [OR] 5 2.72, 95%confidence interval [CI] 1.94-3.82) and stroke (adjusted OR 5 3.72, 95% CI 2.22-6.23). Conclusions: These remarkably heightened odds highlight the exigent need for targeted interventions and prevention strategies addressing modifiable risk factors for CVD in individuals with SCI. © 2013 American Academy of Neurology.

Simons F.E.R.,University of Sfax
Journal of Allergy and Clinical Immunology | Year: 2010

Anaphylaxis occurs commonly in community settings. The rate of occurrence is increasing, especially in young people. Understanding potential triggers, mechanisms, and patient-specific risk factors for severity and fatality is the key to performing appropriate risk assessment in those who have previously experienced an acute anaphylactic episode. The diagnosis of anaphylaxis is based primarily on clinical criteria and is valid even if the results of laboratory tests, such as serum total tryptase levels, are within normal limits. Positive skin test results or increased serum specific IgE levels to potential triggering allergens confirm sensitization but do not confirm the diagnosis of anaphylaxis because asymptomatic sensitization is common in the general population. Important patient-related risk factors for severity and fatality include age, concomitant diseases, and concurrent medications, as well as other less well-defined factors, such as defects in mediator degradation pathways, fever, acute infection, menses, emotional stress, and disruption of routine. Prevention of anaphylaxis depends primarily on optimal management of patient-related risk factors, strict avoidance of confirmed relevant allergen or other triggers, and, where indicated, immunomodulation (eg, subcutaneous venom immunotherapy to prevent Hymenoptera sting-triggered anaphylaxis, an underused, potentially curative treatment). The benefits and risks of immunomodulation to prevent food-triggered anaphylaxis are still being defined. Epinephrine (adrenaline) is the medication of first choice in the treatment of anaphylaxis. All patients at risk for recurrence in the community should be equipped with 1 or more epinephrine autoinjectors; a written, personalized anaphylaxis emergency action plan; and up-to-date medical identification. Improvements in the design of epinephrine autoinjectors will help to optimize ease of use and safety. Randomized controlled trials of pharmacologic agents, such as antihistamines and glucocorticoids, are needed to strengthen the evidence base for treatment of acute anaphylactic episodes. © 2010 American Academy of Allergy, Asthma & Immunology.

Fakhfakh M.,University of Sfax | Pierzchala M.,Wroclaw University of Technology
Radioengineering | Year: 2013

This paper proposes a novel idea for the synthesis of active filters that is based on the use of signal-flow graph (SFG) stamps of differential difference current conveyors (DDCCs). On the basis of an RLC passive network or a filter symbolic transfer function, an equivalent SFG is constructed. DDCCs' SFGs are identified inside the constructed 'active' graph, and thus the equivalent circuit can be easily synthesized. We show that the DDCC and its 'derivatives', i.e. differential voltage current conveyors and the conventional current conveyors, are the main basic building blocks in such design. The practicability of the proposed technique is showcased via three application examples. Spice simulations are given to show the viability of the proposed technique.

Ravichandran K.,King Faisal Specialist Hospital And Research Center | Mohamed G.,Disease Control Strategy Group | Al-Hamdan N.A.,University of Sfax
Asian Pacific Journal of Cancer Prevention | Year: 2010

Background: Earlier studies on cancer knowledge/awareness from Saudi Arabia have been few and mostly limited to knowledge of and attitude towards breast cancer. The objectives of the present cross sectional study were to determine the levels of knowledge concerning cancer and to identify associated factors. Methods: This study was carried out among 1,407 Saudis who were either patients or their escorts, attending selected hospitals in Riyadh region and aged 15 years or more. Required information was obtained by interview using a piloted Arabic questionnaire. Associations between different variables and respondents knowledge were evaluated by Chi square test. Multiple logistic regression analyses were performed to examine the potential impact of the variables. Results: This study population consisted of 688 males and 719 females. Approximately two thirds of participants (67.6%) had never heard of any cancer warning signals, but 80.7% believed some cancers can be cured if detected early, 27.1% believed cancer means end of life and 74.2% believed cancer will appear overnight. The majority of the respondents (65.1%) received information about cancer from television/radio. Although 1,159 had high level knowledge (scored 50.0% and more), only 233 individuals scored 75.0% and more. Significant differences in the knowledge level across age groups, educational levels and marital status were observed. Females had higher level knowledge than males. Odds of having high level knowledge about cancer was 5.27 times higher among those who had undergone any of the tests (breast self examination, mammography, occult blood, Papanicolau smear) compared to those who had none of those tests (95% CI: 1.87-14.84). Those who had heard about any cancer warning signal were more knowledgeable (OR=1.55; 95% CI: 1.10-2.19) than those who hadn't. The other most important determinants of knowledge level included age, and attending a primary health care centre. Conclusions: Our results suggest that the knowledge of cancer is poor among the public and greater attempts should be made to increase public awareness.

Boucetta R.,University of Sfax
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2015

A strategy of path planning with fuzzy logic for a telerobotic assistant surgery is presented in this paper. Telerobotic surgery occurred a long track in its short history. While teleconsultation proceeds to be used today, the advent of high speed communications and increased computational competence is making long distance remote control of operating instruments, called telepresence surgery, a reality. Based on laparoscopic technology, telerobotic surgery was tested first on animals and, more recently, on humans with success. The technology offers several advantages, including improved accuracy and the capability to bring difficult procedures to rural and remote locations where trained surgeons are not available. A dynamic model is computed first for the telerobots using Lagrange formulation. A fuzzy control strategy is used in order to validate the path planning method and the theoretical developments in motion constraints analysis. The paper is ended with a conclusion. © IFIP International Federation for Information Processing 2015.

Etemad-Sajadi R.,University of Applied Sciences and Arts Western Switzerland | Ghachem L.,University of Sfax
Computers in Human Behavior | Year: 2015

Abstract The objective of this paper is to examine the impact of avatars' utilitarian and hedonic values on the different dimensions of e-service quality. Despite the existence of many studies focusing on the impact of the avatar on user's online experience, there is a lack of research on the effect of avatars' values on the different dimensions of websites' perceived quality. We asked respondents to interact with an avatar and then fill in our questionnaire. We applied this process to 8 different service companies' websites with an avatar already integrated. We received 945 questionnaires back. In order to measure e-service quality, we used WEBQUAL. As we had several latent variables, we used partial least squares (PLS), a variance-based structural equation modeling method. Results show that the utilitarian and hedonic values of the avatar increase significantly the perception of the website's quality. The utilitarian value of the avatar impacts 9 of the 10 dimensions of e-service quality. The hedonic value impacts 5 of the 10 dimensions of e-service quality. The results of this study are relevant to the academic world, as we identified that the utilitarian value of an avatar can impact nearly all dimensions of WEBQUAL. Our results can also have immediate and direct implications for companies who want to improve a specific dimension of their website by the use of an avatar. Moreover, this study will be useful for developers of online agents in order to adjust the knowledge of their avatars to clients' and users' needs. © 2015 Elsevier Ltd.

Chtourou Y.,University of Sfax | Fetoui H.,University of Sfax | Jemai R.,University of Sfax | Ben Slima A.,University of Sfax | And 2 more authors.
European Journal of Pharmacology | Year: 2015

Nonalcoholic fatty liver disease (NAFLD) is a spectrum of hepatic abnormalities that extends from isolated steatosis to non-alcoholic steatohepatitis (NASH) and steatofibrosis. NASH is the progressive form of the disease that can lead to fibrosis, cirrhosis and hepatocellular carcinoma. Naringenin (NGEN), a healthful food, increases resistance to oxidative stress, inflammation and protects against multiple organ injury in various animal models. However, specific mechanisms responsible for such effects are poorly understood. Thus, this study investigates the effect of treatment with NGEN (50 mg/kg) on oxidative events and the molecular mechanisms underlying inflammatory changes triggered in the rat liver by a high cholesterol diet for 90 days. NGEN significantly decreased the plasma fatty acid composition, the hepatic pro-inflammatory mediators and the expression of relevant genes including tumor necrosis factor-α, interlukin-6, interleukin-1β, inducible nitric oxide synthase and matrix metalloproteinases (MMP-2, 9), EGF-like module-containing mucin-like hormone receptor-like 1 (macrophage F4/80-specific gene); which suggests a reduced macrophage infiltration, and inhibited oxidative stress related biomarker levels at the end point of the experiment. Mechanistically, studies showed that NGEN markedly reduced lipid and protein oxidations, recruited the anti-oxidative defense system and promoted extracellular matrix degradation by modulating the levels of necrotic inflammation. © 2014 Elsevier B.V. All rights reserved.

Mabrouk L.,University of Sfax | Hamza A.,Institute National Des Science Et Des Technology Of La Mer Of Sfax | Brahim M.B.,University of Sfax | Bradai M.-N.,Institute National Des Science Et Des Technology Of La Mer Of Sfax
Aquatic Botany | Year: 2013

We investigated the impact of sewage discharge on Posidonia oceanica meadows in Eastern Tunisia (Mahdia). We specifically addressed changes in plant growth and epiphyte composition on leaves and rhizomes caused by this anthropogenic interference. A hierarchical sampling design was used to compare epiphyte biomass and community structure between one disturbed and two control stations. Samples were collected by SCUBA diving at 8. m depth in August 2009. A total of 44 taxa, macroinvertebrates and macroalgae, were identified on rhizomes, and 27 taxa on leaves. In the disturbed station, leaf length, leaf surface area and the leaf area index decreased, whereas epiphyte biomass increased compared to the control stations. Rhizome epiphyte coverage differed significantly between the control stations and the disturbed station, mainly due to changes in green, red and brown algae, bryozoans, and ascidians. Leaf epiphyte coverage differed between stations, with more red algae and ascidians on leaves of the disturbed station and more, green and brown algae at the control stations. SIMPER and CCA analyses showed that differences were due to the absence of some species at the control stations, which exhibited a high coverage at the polluted station.In summary, waste water pollution caused a severe deterioration of seagrass meadow vitality, possibly due to an increased epiphyte cover and associated changes in epiphyte community composition on leaves and rhizomes of P. oceanica. © 2013 Elsevier B.V.

Gauthier G.,Université de Sherbrooke | St-Onge C.,Université de Sherbrooke | Tavares W.,McMaster University | Tavares W.,Centennial College | Tavares W.,University of Sfax
Medical Education | Year: 2016

Background: Given the complexity of competency frameworks, associated skills and abilities, and contexts in which they are to be assessed in competency-based education (CBE), there is an increased reliance on rater judgements when considering trainee performance. This increased dependence on rater-based assessment has led to the emergence of rater cognition as a field of research in health professions education. The topic, however, is often conceptualised and ultimately investigated using many different perspectives and theoretical frameworks. Critically analysing how researchers think about, study and discuss rater cognition or the judgement processes in assessment frameworks may provide meaningful and efficient directions in how the field continues to explore the topic. Methods: We conducted a critical and integrative review of the literature to explore common conceptualisations and unified terminology associated with rater cognition research. We identified 1045 articles on rater-based assessment in health professions education using Scorpus, Medline and ERIC and 78 articles were included in our review. Results: We propose a three-phase framework of observation, processing and integration. We situate nine specific mechanisms and sub-mechanisms described across the literature within these phases: (i) generating automatic impressions about the person; (ii) formulating high-level inferences; (iii) focusing on different dimensions of competencies; (iv) categorising through well-developed schemata based on (a) personal concept of competence, (b) comparison with various exemplars and (c) task and context specificity; (v) weighting and synthesising information differently, (vi) producing narrative judgements; and (vii) translating narrative judgements into scales. Conclusion: Our review has allowed us to identify common underlying conceptualisations of observed rater mechanisms and subsequently propose a comprehensive, although complex, framework for the dynamic and contextual nature of the rating process. This framework could help bridge the gap between researchers adopting different perspectives when studying rater cognition and enable the interpretation of contradictory findings of raters' performance by determining which mechanism is enabled or disabled in any given context Discuss ideas arising from the article at www.mededuc.com discuss. © 2016 John Wiley & Sons Ltd.

Leveque N.,University Hospital | Leveque N.,University of Sfax | Renois F.,University Hospital | Renois F.,University of Sfax | And 2 more authors.
Clinical Microbiology and Infection | Year: 2013

Molecular diagnostic techniques for viral testing have undergone rapid development in recent years. They are becoming more widely used than the classical virological assays in the majority of clinical virology laboratories, and now represent a new method for the diagnosis of human viral infections. Recently, new techniques based on multiplex RT-PCR amplification followed by microarray analysis have been developed and evaluated. On the basis of amplification of viral genome-specific fragments by multiplex RT-PCR and their subsequent detection via hybridization with microorganism-specific binding probes on solid surfaces, they allow simultaneous detection and identification of multiple viruses in a single clinical sample. The management of viral central nervous system and respiratory tract infections currently represents the two main applications of the microarrays in routine virological practice. Microarrays have shown reliable results in comparison with those of referenced (RT)-PCR assays, and appear to be of major interest for the detection of a broad range of respiratory and neurotropic viruses, assessment of the pathogenicity of newly discovered or neglected viruses, and identification of multiple viral infections in clinical samples. Despite several limitations observed during the different studies performed, this new technology might improve the clinical management of patients by enlarging the range of the viruses detected, in particular in cases of severe infections leading to patient hospitalization in the intensive-care unit. They might also help in the prevention of nosocomial transmission in hospital departments by contributing to the development of new epidemiological surveillance systems for viral infections. © 2012 The Authors. Clinical Microbiology and Infection © 2012 European Society of Clinical Microbiology and Infectious Diseases.

Ammar M.,University of Sfax | Chtourou W.,University of Sfax | Driss Z.,University of Sfax | Abid M.S.,University of Sfax
Energy | Year: 2011

The aim of this paper is to study the hydrodynamic behavior induced by a three different turbines: the FBT6 (six flat blades turbine), the RT6 (Rushton turbine), the PBT6 (pitched blades turbine). The turbulent flow generated in stirred tanks is numerically predicted by the resolution of the Navier-Stokes equation in conjunction with the RNG (Renormalization Group) of the k-ε turbulent model. These equations are solved by a control volume discretization method. The measurements were carried out for the one-stage and two-stage systems. The numerical results from the application of the CFD (computational fluid dynamics) code Fluent with the MRF (Multi Reference Frame) model are presented in the vertical and horizontal planes in the impeller stream region. The comparison between the numerical results and the experimental data showed a good agreement. © 2011 Elsevier Ltd.

Ghattas M.H.,University of Sfax | Abo-Elmatty D.M.,Suez Canal University | El-Eraki A.Z.,Suez Canal University
Journal of Cardiovascular Medicine | Year: 2012

AIMS: High-sensitivity C-reactive protein (hs-CRP) is an inflammatory marker, predicting the occurrence of acute myocardial infarction (AMI). Genetic predisposition to high baseline CRP might account for a high risk of heart diseases. Our study aimed at investigating an association of CRP 1059G/C gene polymorphism with plasma CRP levels and AMI in Egyptian patients. METHODS: Genotypes of 150 patients with AMI and 150 healthy sex and age-matched controls were analyzed using PCR-restriction fragment length polymorphism methods. hs-CRP concentrations were assessed. RESULTS: There was no significant association between CRP 1095G/C polymorphism and AMI. However, individuals with GG genotype had significantly higher plasma CRP concentration than those with GC and CC genotypes, in both controls (3.82±1.03 vs. 2.34±0.7; P=0.001) and patients with AMI (8.39±2.6 vs. 6.67±2.4; P=0.005). CONCLUSION: Our results revealed that CRP 1059G/C gene variation influences plasma CRP levels. Conversely, this polymorphism was not associated with the risk for AMI. © 2012 Italian Federation of Cardiology.

Pepermans G.,University of Sfax | Pepermans G.,Catholic University of Leuven
Energy Policy | Year: 2011

This paper estimates the willingness to pay/accept (WTP/WTA) of Flemish households for continuous power supply, based on a stated preference approach. The data were collected via a choice experiment and were then used to estimate a main effects conditional logit model and a random parameter logit model with interaction effects and correlated preferences. Power outages are characterized by 6 attributes: annual frequency, duration, peak or off peak, announced or unannounced, winter or summer and invoice impact. All estimates have the expected sign. The results are used to assess the marginal WTP/WTA for each of these attributes. Overall, the outcome suggests that Flemish households have heterogeneous preferences regarding power outage attributes, and that, due to a status quo bias, only a relatively small share of them is willing to switch to a lower reliability level if this would be compensated by a bill discount. © 2011 Elsevier Ltd.

Over the last decade, APETALA2/Ethylene Responsive Factor (AP2/ERF) proteins have become the subject of intensive research activity due to their involvement in a variety of biological processes. This research led to the identification of AP2/ERF genes in many species; however, little is known about these genes in durum wheat, one of the most important cereal crops in the world. In this study, a new member of the AP2/ERF transcription factor family, designated TdSHN1, was isolated from durum wheat using thermal asymetric interlaced PCR (TAIL-PCR) method. Protein sequence analysis showed that TdSHN1 contained an AP2/ERF domain of 63 amino acids and a putative nuclear localization signal (NLS). Phylogenetic analysis showed that TdSHN1 belongs to a group Va protein in the ERF subfamily which contains the Arabidopsis ERF proteins (SHN1, SHN2, and SHN3). Expression of TdSHN1 was strongly induced by salt, drought, abscisic acid (ABA), and cold. In planta, TdSHN1 protein was able to activate the transcription of GUS reporter gene driven by the GCC box and DRE element sequences. In addition, TdSHN1 was targeted to the nucleus when transiently expressed in tobacco epidermal cells. In transgenic yeast, overexpression of TdSHN1 increased tolerance to multiple abiotic stresses. Taken together, the results showed that TdSHN1 encodes an abiotic stress-inducible, transcription factor which confers abiotic stress tolerance in yeast. TdSHN1 is therefore a promising candidate for improvement of biotic and abiotic stress tolerance in wheat as well as other crops. © 2015, Springer-Verlag Wien.

Horchani H.,University of Sfax | Chaabouni M.,University of Sfax | Gargouri Y.,University of Sfax | Sayari A.,University of Sfax
Carbohydrate Polymers | Year: 2010

Starch is an abundant natural polysaccharide that is inexpensive, renewable, and fully biodegradable. Modification of starch O-H groups by esterification to form an appropriate degree of substitution imparts thermoplasticity and water resistance to the starch ester over the unmodified starch. Unlike chemical esterification, enzymatic esterification is an environmentally friendly method which occurs under milder conditions. A non-commercial CaCO3-immobilized lipase from Staphylococcus aureus (SAL3) was used to catalyze the esterification reaction between oleic acid and starch in pure substrate conditions using microwave heating followed by liquid state esterification. Response surface methodology based on three variables (the reaction temperature, the amount of lipase and the molar ratio of starch/oleic acid) at three levels was adopted to optimize the experimental conditions of the starch oleate synthesis. The optimal conditions for achieving 76% conversion with a degree of substitution (DS) of 2.86 are 386 IU of immobilized lipase, a starch/oleicacid molar ratio of 0.18 during 4 h of incubation at 44 °C. The structure of the modified starch was checked by 13C NMR spectroscopy, FT-IR and differential scanning calorimetry (DSC). Results showed that the α-amylolysis of the starch was significantly affected after esterification. The hydrophobic starch fatty acid esters produced may have potential industrial applications such as surface coating materials, flavoring agents in food industry and biomedicals for bone fixation and replacements. © 2009 Elsevier Ltd. All rights reserved.

In the paper [A. Ben Amar, A. Jeribi, and B. Krichen, Fixed point theorems for block operator matrix and an application to a structured problem under boundary conditions of Rotenberg's model type, to appear in Math. Slovaca. (2014)], the existence of solutions of the two-dimensional boundary value problem (1) and (2) was discussed in the product Banach space L(p)×L(p) for p∈(1, ∞). Due to the lack of compactness on L1 spaces, the analysis did not cover the case p=1. The purpose of this work is to extend the results of Ben Amar et al. to the case p=1 by establishing new variants of fixed-point theorems for a 2×2 operator matrix, involving weakly compact operators.

van der Laan H.P.,University of Groningen | Hurkmans C.W.,Catharina Hospital | Kuten A.,University of Sfax | Westenberg H.A.,Institute for Radiation Oncology Arnhem
Radiotherapy and Oncology | Year: 2010

Purpose: To evaluate the current technological clinical practice of radiation therapy of the breast in institutions participating in the EORTC-Radiation Oncology Group (EORTC-ROG). Materials and methods: A survey was conducted between August 2008 and January 2009 on behalf of the Breast Working Party within the EORTC-ROG. The questionnaire comprised 32 questions on 4 main topics: fractionation schedules, treatment planning methods, volume definitions and position verification procedures. Results: Sixty-eight institutions out of 16 countries responded (a response rate of 47%). The standard fraction dose was generally 2 Gy for both breast and boost treatment, although a 2.67 Gy boost fraction dose is routinely given in British institutions. The main boost modality was electrons in 55%, photons in 47% and brachytherapy in 3% of the institutions (equal use of photon and electron irradiation in 5% of the institutions). All institutions used CT-based treatment planning. Wide variations are seen in the definition of the breast and boost target volumes, with margins around the resection cavity, ranging from 0 to 30 mm. Inverse planned IMRT is available in 27% and breath-hold techniques in 19% of the institutions. The number of patients treated with IMRT and breath-hold varied per institution. Electronic portal imaging for patient set-up is used by 92% of the institutions. Conclusions: This survey provides insight in the current practice of radiation technology used in the treatment of breast cancer among institutions participating in EORTC-ROG clinical trials. © 2010 Elsevier Ireland Ltd. All rights reserved.

Kaya S.,Hacettepe University | Akbayrak T.,Hacettepe University | Beksac S.,University of Sfax
Clinical Rehabilitation | Year: 2011

Objective: To investigate and compare the effectiveness of various treatment protocols for the treatment of women with idiopathic detrusor overactivity. Design: Prospective, randomized controlled trial. Setting: Departments of Physiotherapy and Rehabilitation and Obstetrics and Gynaecology, Hacettepe University. Subjects: Forty-six subjects were randomized to three groups. Interventions: The first group received only pharmacotherapy, the second group received only physiotherapy and in the third group pharmacotherapy was combined with physiotherapy (combined therapy group). Main measures: All patients were evaluated at the beginning and at the end of treatment. Assessment parameters were maximum cystometric capacity, electromyographic activity of pelvic floor muscles, voiding diary parameters, the amount of urine leakage and the quality of life score. Results: The maximum cystometric capacity and the electromyographic activity of pelvic floor muscles increased significantly and the number of voids/day and incontinence episodes/day, and the amount of urine leakage reduced significantly (P<0.05) in both physiotherapy and combined therapy groups while there was no significant difference in the pharmacotherapy group. After treatment, the number of voids/day increased by 0.3±3.4 in the pharmacotherapy group (P>0.05) and decreased by 5.1±5.5 and 4.7±5.6 in the physiotherapy and combined therapy groups, respectively (P<0.05). Statistically significant improvements were observed in all groups according to the number of voids/night and the quality of life scores at the end of the treatment. Conclusion: The physiotherapy protocol we introduced in the present study with or without anticholinergic therapy has a substantial positive impact on the treatment of female patients with idiopathic detrusor overactivity. © The Author(s), 2010.

Al-Zalabani A.H.,University of Sfax
Saudi Medical Journal | Year: 2011

Researchers looking for health statistics on the Kingdom of Saudi Arabia (KSA) may face difficulty. This is partly due to the lack of awareness of potential sources where such statistics can be found. The purpose of this paper is to review various online sources of health statistics on KSA, and to highlight their content, coverage, and presentation of health statistics. Five bibliographic databases where local research can be found are described. National registries available are summarized. Governmental agencies, as well as societies and centers where the bulk of health statistics is produced are also described. Finally, some potential international sources that can be used for the purpose of comparison are presented.

Nali H.,University of Sfax
Journal of Coordination Chemistry | Year: 2012

Two new noncentrosymmetric polar zinc sulfates have been synthesized by slow evaporation through the use of enantiomorphically pure sources of either (R)-2-methylpiperazine or (S)-2-methylpiperazine. A centrosymmetric analog was also prepared using a racemic source of the amine. The 3-D structure networks for these compounds consist of isolated [Zn(H 2O) 6] 2+, [C 5H 14N 2] 2+, and linked by hydrogen bonds. The use of racemic 2-methylpiperazine results in crystallographic disorder of the amines and creation of inversion centers, while using a single enantiomer destroys the inversion symmetry and orders of the amines. These structures were determined using single-crystal X-ray diffraction, infrared spectroscopy, and thermal analyses. Crystal data are as follows: [C 5H 14N 2][Zn(H 2O) 6](SO 4) 2 (1), a=6.5988(1)Å, b=10.9613(2)Å, c=12.5479(2)Å, β=101.385(1)°, V=889.75(3)Å 3, P 21/n (No. 14), Z=2; [(R)-C 5H 14N 2][Zn(H 2O) 6](SO 4) 2 (2), a=10.8665(2)Å, b=7.8600(1)Å, c=11.7029(2)Å, β=116.283(1)°, V=896.22(3)Å 3, P 21 (No. 4), Z=2; [(S)-C 5H 14N 2][Zn(H 2O) 6](SO 4) 2 (3), a=6.5819(2)Å, b=11.0014(2)Å, c=12.5229(3)Å, β=101.489(1)Å, V=888.62(4)Å 3, P 21 (No. 14), Z=2. © 2012 Copyright Taylor and Francis Group, LLC.

Haaj S.B.,University of Sfax | Thielemans W.,Catholic University of Leuven | Magnin A.,CNRS Rheology Laboratory | Boufi S.,University of Sfax
ACS Applied Materials and Interfaces | Year: 2014

Latex/starch nanocrystal (SNC) nanocomposite dispersions were successfully synthesized via a one-step surfactant-free Pickering emulsion polymerization route using SNC as the sole stabilizer. The effect of the SNC content, initiator type and comonomer on the particle size, colloidal stability, and film properties were investigated. Both HCl and H2SO4- hydrolysed starch nanocrystals, each bearing different surface charges, were used as Pickering emulsion stabilizing nanoparticles. SNCs from HCl hydrolysis were found to provide a better stabilization effect, giving rise to a polymer dispersion with a lower average particle size. The mechanistic aspects of the Pickering emulsion polymerization were also discussed. Nanocomposites formed by film-casting the polymer Pickering emulsions showed better mechanical properties and optical transparency than those obtained by blending the polymer emulsion with a nanocrystal dispersion, showing the one-pot route to nanocomposite precursors to be doubly advantageous. Therefore, this in situ polymerization technique not only facilitates the use of SNC nanoparticles, it also provides a valuable nanocomposite with enhanced mechanical properties and high transparency level. © 2014 American Chemical Society.

Kalia S.,University of Bologna | Kalia S.,BAHRA University | Boufi S.,University of Sfax | Celli A.,University of Bologna | Kango S.,Jaypee University of Information Technology
Colloid and Polymer Science | Year: 2014

Interest in nanofibrillated cellulose has been increasing exponentially because of its relatively ease of preparation in high yield, high specific surface area, high strength and stiffness, low weight and biodegradability etc. This bio-based nanomaterial has been used mainly in nanocomposites due to its outstanding reinforcing potential. Solvent casting, melt mixing, in situ polymerization and electrospinning are important techniques for the fabrication of nanofibrillated cellulose-based nanocomposites. Due to hydrophilic character along with inherent tendency to form strong network held through hydrogen-bonding, nanofibrillated cellulose cannot uniformly be dispersed in most non-polar polymer matrices. Therefore, surface modification based on polymer grafting, coupling agents, acetylation and cationic modification was used in order to improve compatibility and homogeneous dispersion within polymer matrices. Nanofibrillated cellulose opens the way towards intense and promising research with expanding area of potential applications, including nanocomposite materials, paper and paperboard additive, biomedical applications and as adsorbent. © 2013 Springer-Verlag Berlin Heidelberg.

Westall C.A.,University of Sfax | Cortese F.,University of Sfax | Cortese F.,University of Calgary | Snead O.C.,University of Toronto | Buncic J.R.,University of Sfax
Neurology | Year: 2014

Objectives: To determine time to vigabatrin (VGB, Sabril; Lundbeck, Deerfield, IL) induced retinal damage in children with infantile spasms (IS) and to identify risk factors forVGB-induced retinal damage (VGB-RD). Methods: Observational cohort study including 146 participants (68 female, 81 male) with IS, an age-specific epilepsy syndrome of early infancy, treated with VGB. Participants ranged from 3 to 34.9 months of age (median 7.6 months). The median duration of VGB treatment was 16 months (range 4.6-78.5 months). Electroretinograms (ERGs) were performed according to the Standards of the International Society for Clinical Electrophysiology of Vision. Inclusion required baseline (pre-VGB or within 4 weeks of starting VGB treatment) and at least 2 follow-up ERGs. Significant reduction from baseline of the 30-Hz ERG flicker amplitude on 2 consecutive visits identified VGB-RD. Kaplan-Meier survival analyses depicted the effect of duration of VGB on VGB-RD. Results: These data represent the largest survival analysis of children treated with VGB who did not succumb to retinal toxicity during the study. Thirty of the 146 participants (21%) showed VGB-RD. The ERG amplitude reduced with duration of VGB treatment (p 5 0.0004) with no recovery after VGB cessation.With 6 and 12months of VGB treatment, 5.3%and 13.3%, respectively, developed VGB-RD. There was neither effect of age of initiation of VGB treatment nor sex of the child on survival statistics and no significant effect of cumulative dosage on the occurrence of VGB-RD. Conclusions: Minimizing VGB treatment to 6 months will reduce the prevalence of VGB-RD in patients with IS. © 2014 American Academy of Neurology.

Garcia-Carmona J.-A.,University of Sfax | Milanes M.-V.,University of Sfax | Laorden M.-L.,University of Sfax
International Journal of Neuropsychopharmacology | Year: 2013

This study examined the involvement of the brain stress system in the reinforcing effects of morphine. One group of mice was conditioned to morphine using the conditioned place preference (CPP) paradigm and the other group received morphine in a home-cage (non-conditioned). Adrenocorticotropic hormone and corticosterone levels were measured by radioimmunoassay; phospho (p) CREB expression and the number of corticotropin-releasing factor (CRF) neurons and fibres were measured by immunohistochemistry in different brain areas. We observed that the number of CRF neurons in the paraventricular nucleus (PVN) was increased after morphine-induced CPP, which was paralleled with enhanced CRF-immunoreactivity fibres in the nucleus tractus solitarius (NTS) and ventral tegmental area (VTA) vs home-cage group injected with morphine. Morphine exposure induced an increase in CREB phosphorylated at Ser133 in the PVN and central amygdale (CeA), whereas mice exhibiting morphine CPP had higher levels of pCREB in the PVN, CeA and bed nucleus of the stria terminalis (BNST). We also found that most of the CRF-positive neurons in the PVN, CeA and BNST co-express pCREB after morphine CPP expression, suggesting that the drug-Associated environmental contexts can elicit neuronal activity in the brain stress system. From the present results it is clear that exposure to a drug-Associated context remains a potent activator of signalling pathways leading to CRF activation in the brain stress system. © © CINP 2013Â.

Saad M.F.,Gafsa University | Alimi A.M.,University of Sfax
2010 2nd International Conference on Image Processing Theory, Tools and Applications, IPTA 2010 | Year: 2010

This paper presents a study on the fuzzy classification techniques that have been applied to the MR images. The goal is to improve the fuzzy techniques in inventing a new classification method, called the Improved Modified Suppressed Fuzzy C-Means (IMS-FCM) which modifies another algorithm called Modified Suppressed Fuzzy C-Means (MS-FCM). The latter one works with a common parameter α based on the exponential separation strength between clusters in each iteration in order to modify the memberships degrees of the pixels and to accelerate in consequence the convergence of the standard algorithm FCM to the optimum. It's not logical because the context differs from one pixel to another. To overcome this disadvantage we propose a new version of MS-FCM taking account of noie aspect . The former aspect is treated by a new parameter called the degree of cleanness of the pixel relatively to a class instead of α. We test the new algorithm and the FCM, S-FCM and MS-FCM algorithms in many magnetic resonance images. Overall, the new algorithm gives better results than the others. ©2010 IEEE.

Fantazzini D.,Moscow State University | Toktamysova Z.,University of Sfax
International Journal of Production Economics | Year: 2015

Long-term forecasts are of key importance for the car industry due to the lengthy period of time required for the development and production processes. With this in mind, this paper proposes new multivariate models to forecast monthly car sales data using economic variables and Google online search data. An out-of-sample forecasting comparison with forecast horizons up to 2 years ahead was implemented using the monthly sales of ten car brands in Germany for the period from 2001M1 to 2014M6. Models including Google search data statistically outperformed the competing models for most of the car brands and forecast horizons. These results also hold after several robustness checks which consider nonlinear models, different out-of-sample forecasts, directional accuracy, the variability of Google data and additional car brands. © 2015 Elsevier B.V. All rights reserved.

Rehacek P.,University of Sfax
Proceedings of the 11th International Conference on Strategic Management and Its Support by Information Systems 2015, SMSIS 2015 | Year: 2015

In present, projectized organizational structure and mainly cross-functional management is a research topic given the multitude of the cross-functional organizations that are founded and whose advantages are unanimous recognized. The old hierarchical pyramid was suitable for companies a long while during the industrial era. But nowadays they are not at all seen as profitable organizations. The aim of this paper is to present the main features of the organizational structure for project management, their advantages and disadvantages.

Derbel S.,University of Sfax | Chaieb M.,University of Sfax
African Journal of Ecology | Year: 2013

Henophyton deserti, Calligonum polygonoides, Ephedra alata and Anthyllis henoniana may be suitable Saharan species for the rehabilitation of degraded lands. In this context, the phenology, excavation of root systems and seedling establishment of these species were investigated in the southern Tunisia. Our data suggest that phenological differences between the studied species may depend on the rooting depth. The mean seedling emergence rate was 73% in H. deserti, 66% in A. henoniana, 60% in C. polygonoides and 50% in E. alata. Statistical analyses of seedling establishment showed a highly significant difference among the four species in both seasons (F = 1595.15, P < 0.0001), species (F = 781.57, P < 0.0001) and species/season interaction (F = 61.84, P < 0.0001). After 3 years, seedling mortality ranged from 73% to 89%. Seedling mortality reached a maximum in the summer of the first year of study (P < 0.001). This study provided further understanding of the ecological tolerance, adaptive strategy and the low density of these species in nature. Henophyton deserti appears to be better adapted to the harsh desert environment. These findings explain the very high density observed in the Sahara compared with other studied species. This species has therefore proven to be an excellent candidate for the ecological restoration of degraded desert rangelands and can be introduced successfully in to rehabilitation programmes. © 2012 Blackwell Publishing Ltd.

Masmoudi S.,University of Sfax | Denis M.,French National Center for Scientific Research | Maalej S.,University of Sfax
Marine Pollution Bulletin | Year: 2010

We have investigated the fate of Staphylococcus aureus by starving the cells and maintaining them in natural seawater at 22 and 4 °C. At 22 °C, cells developed a long-term survival state where about 0.037% of the initial population remained culturable over more than 7 months, whereas at 4 °C, bacteria lost culturability and transiently entered into the viable but non-culturable state (VBNC). However, after 22 days of entry into the VBNC state, the number of viable cells detected via the direct viable count method decreased significantly. We show here that mutational inactivation of catalase (KatA) or superoxide dismutase (SodA) rendered strains hypersensitive to seawater stress at 4 °C and consequently, part of the seawater lethality on S. aureus at low temperature is mediated by reactive oxygen species (ROS) during microcosm-survival process. Shifting the temperature from 4 to 22 °C of totally non-culturable wild-type cells induced a partial recovery of the population. However, deficiencies in catalase or superoxide dismutase prevent resuscitation ability. © 2010 Elsevier Ltd.

Sonnewald U.,Norwegian University of Science and Technology | Sonnewald U.,University of Sfax
Journal of Neurochemistry | Year: 2014

The central process in energy production is the oxidation of acetyl-CoA to CO2 by the tricarboxylic acid (TCA, Krebs, citric acid) cycle. However, this cycle functions also as a biosynthetic pathway from which intermediates leave to be converted primarily to glutamate, GABA, glutamine and aspartate and to a smaller extent to glucose derivatives and fatty acids in the brain. When TCA cycle ketoacids are removed, they must be replaced to permit the continued function of this essential pathway, by a process termed anaplerosis. Since the TCA cycle cannot act as a carbon sink, anaplerosis must be coupled with cataplerosis; the exit of intermediates from the TCA cycle. The role of anaplerotic reactions for cellular metabolism in the brain has been studied extensively. However, the coupling of this process with cataplerosis and the roles that both pathways play in the regulation of amino acid, glucose, and fatty acid homeostasis have not been emphasized. The concept of a linkage between anaplerosis and cataplerosis should be underscored, because the balance between these two processes is essential. The hypothesis that cataplerosis in the brain is achieved by exporting the lactate generated from the TCA cycle intermediates into the blood and perivascular area is presented. This shifts the generally accepted paradigm of lactate generation as simply derived from glycolysis to that of oxidation and might present an alternative explanation for aerobic glycolysis. © 2014 International Society for Neurochemistry.

Fdhila R.,University of Sfax | Hamdani T.M.,University of Sfax | Alimi A.M.,University of Sfax
ISCIII 2011 - 5th International Symposium on Computational Intelligence and Intelligent Informatics | Year: 2011

In this paper, a new Multi-Objective Particle Swarm Optimization (MOPSO) is applied to solve a problem of feature selection defined as a multiobjective problem. This algorithm (pMOPSO), known for its fast convergence with negligible computation time is based on a distributed architecture. Sub-swarms are obtained from dynamic subdivision of the population using Pareto Fronts. The algorithm addresses a problem defined by two goals, characterized by their contradictory aspect, namely, minimizing the error rate and minimizing the number of features. The two objectives are treated simultaneously constituting the objective function. Performance of our approach is compared with other evolutionary techniques using databases choosing from the UCI repository [1]. © 2011 IEEE.

During the last three decades, a series of paleontological and biological results have brought considerable changes to the long-standing question of a possible relationship between the Paleozoic and modern corals. Microstructural descriptions of samples from the alpine outcrops (Salzkammergut and Dolomites) along with new specimens from Turkey have shown first that the classical Wells' scheme have to be re-examined. Accordingly, several investigations based on molecular phylogeny have repeatedly led to the conclusion that, at the family level, the taxonomy inherited from Vaughan and Wells cannot be maintained. From an overall evolutionary viewpoint, agreement also exists between microstructural analysis and molecular phylogeny. A recently discovered Triassic family, the Pachythecalids, exhibits highly unexpected skeletal features and microstructures in both septa and walls. Additionally, structural relationships between walls and septa demonstrate a particular mode of growth, with ontogenic priority to the theca. Comparison of the corallite microstructures suggests that most of the Triassic fauna can be derived from this unique family by an evolutionary process during which the septal system became progressively prevalent upon the wall. This monophyly of the modern corals is also well supported by molecular phylogeny.The present concept of Scleractinia has to be re-examined because it cannot include neither Pachythecalids, probably related to the Late Permian Polycoelids, nor some other post-Paleozoic corals, including extant Guyniidae, with long recognized specific structural patterns. © 2010 Elsevier Ltd and Nanjing Institute of Geology and Palaeontology, CAS.

Bentz D.,University of Basel | Bentz D.,University of Sfax | Michael T.,University of Basel | de Quervain D.J.-F.,University of Sfax | Wilhelm F.H.,University of Basel
Journal of Anxiety Disorders | Year: 2010

Current neurophysiological and psychological accounts view exposure therapy as the clinical analog of extinction learning that results in persistent modifications of the fear memory involved in the pathogenesis, symptomatology, and maintenance of anxiety disorders. Evidence from studies in animals and humans indicate that glucocorticoids have the potential to facilitate the processes that underlie extinction learning during exposure therapy. Particularly, glucocorticoids can restrict retrieval of previous aversive learning episodes and enhance consolidation of memory traces relating to non-fearful responding in feared situations. Thus, glucocorticoid treatment especially in combination with exposure therapy might be a promising approach to optimize treatment of anxiety disorders. This review examines the processes involved in aversive conditioning, fear learning and fear extinction, and how glucocorticoids might enhance restructuring of fear memories during therapy. © 2009 Elsevier Ltd. All rights reserved.

Genest J.,University of Sfax
Canadian Journal of Cardiology | Year: 2010

The inflammatory biomarker high-sensitivity C-reactive protein (hsCRP) has been proposed as a novel instrument to assess cardiovascular risk, to determine the need for statin therapy in specific individuals otherwise not deemed to meet current criteria, and to represent a potential target of treatment. CRP is predominantly secreted by the liver and adipose tissue in response to inflammatory stress and is regulated, in great part, by interleukin- 6. The issue of CRP as a causal factor (rather than a biomarker) has been addressed by three types of studies: animal models, in which CRP was injected; transgenic mice over-expressing human CRP; and Mendelian randomization studies. All indicate that CRP may not have a direct role in promoting atherosclerosis but, instead, serves as a marker of vascular inflammation and the presence of atherosclerosis. Several clinical studies have shown that individuals reaching both low-density lipoprotein cholesterol (LDL-C) and hsCRP targets (LDL-C less than 2.0 mmol/L and hsCRP less than 2 mg/L) have the lowest event rate, suggesting that hsCRP may become a secondary target of treatment after LDL-C. The Justification for the Use of Statins in Prevention: an Intervention Trial Evaluating Rosuvastatin (JUPITER) study showed that apparently healthy men and women with elevated hsCRP, but normal LDL-C (less than 3.4 mmol/L), had an overall 44% reduction in the primary end points with rosuvastatin 20 mg/day. The results of this study have now been incorporated in the new Canadian guidelines for the diagnosis and treatment of dyslipidemia and prevention of cardiovascular disease. © 2010 Pulsus Group Inc.

Tozri A.,University of Sfax | Tozri A.,CNRS Neel Institute | Dhahri E.,University of Sfax | Hlil E.K.,CNRS Neel Institute
Journal of Magnetism and Magnetic Materials | Year: 2010

Study of structural, magnetic and transport properties of the polycrystalline La0.8Pb0.1□0.1MnO3 (LPMO) and La0.8Pb0.1Na0.1MnO3 (LPNMO) samples has been carried out. The X-ray diffraction shows that both samples crystallize in a rhombohedral structure with the R over(3, -) c space group. Ferromagnetic and insulating states are found for the LPMO sample, whereas a ferromagnetic behavior below 247 K and insulator-metal transition at 180 K are observed for the LPNMO sample. The temperature dependence of magnetic susceptibility at higher temperature for both samples reveals the presence of the Griffiths phase above the Curie temperature. The thermal evolution of magnetization in the ferromagnetic phase at low temperature varies as T3/2, in accordance with Bloch's law. The magnetization does not reach complete saturation up to a field of 6 T. Moreover, analysis of cell parameters indicates that the structure of LPMO is more distorted than LPNMO whereas additional results from the unit cell volume and the Curie temperature combined with previous results point to a lower average radius 〈rA〉 (the average ionic radius, related to the one-electron bandwidth) and higher variance σrA 2 (the variance, measuring the quenched disorder) for LPMO reference to LPNMO. This result is in agreement with the enhancement of Griffiths phase characteristics and the low value of the spin stiffness constant D for LPMO. Finally, we show that the magnitude of the magnetic inhomogeneity depends on the random substitution in the A-site cations. © 2010 Elsevier B.V. All rights reserved.

Bouattour S.,University of Sfax | Do Rego A.M.B.,Institute of Nanoscience and Nanotechnology IN | Ferreira L.F.V.,Institute of Nanoscience and Nanotechnology IN
Materials Research Bulletin | Year: 2010

Doped TiO2 particles were synthesized by solid grinding and sol-gel methods. The ensuing powders were analysed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and ground state diffuse reflectance absorption spectroscopy (GSDR). The doped samples prepared by solid grinding at 400 °C were in the anatase form, while those synthesised via sol-gel method and calcinated at the same temperature were dominated by the rutile phase. The X-ray photoelectron spectroscopy (XPS) revealed a surface segregation of the doping elements namely for Y, Rb and Rb-Y. The photocatalytic activity of the prepared catalysts, under sunlight irradiation, was evaluated using 2-naphthol as a pollutant model. Results showed a great enhancement in the photocatalytic efficiency with incorporation of Y in samples prepared by solid grinding, while in samples prepared via sol-gel process both Rb and Y dopants greatly improve the photocatalytic activity. The Langmuir-Hinshelwood model was used to describe thephotocatalytic reactions from which a pseudo-first-order kinetics was established. The repeatability of photocatalytic activity was also tested for several degradation cycles. © 2010 Elsevier Ltd. All rights reserved.

Zhani K.,University of Sfax | Ben Bacha H.,King Saud University
Renewable Energy | Year: 2010

This paper tackles an experimental investigation of a new solar desalination prototype using the humidification dehumidification principle at the weather conditions of Sfax City, Tunisia. The prototype is designed and constructed at the national engineering school of Sfax to conduct this experimental investigation under different meteorological and operating parameters. It is composed of a flat plate solar air collector, a flat plate solar water collector, a humidifier, an evaporation tower and a condensation tower. An economic analysis was conducted, since it affects the final cost of produced water, to determine both the cost of fresh water production and the payback period of the experimental setup. Although a system may be technically very efficient, it may not be economic. The experimental investigation of the dynamic behaviour of the solar desalination unit during summer season (June, July and August) and during a typical day in July was carried to study the temporal evolutions of the temperature of air and water and the relative humidity at the inlet and the outlet of each component of the system. © 2010 Elsevier Ltd.

Afungchui D.,University of Buea | Kamoun B.,University of Sfax | Helali A.,University of Sfax | Ben Djemaa A.,University of Sfax
Renewable Energy | Year: 2010

The aim of this paper is to numerically explore the non-linear two-dimensional unsteady potential flow over a Savonius rotor and to develop a code for predicting its aerodynamics performances. In the model developed, the rotor is represented in a median plane by two semicircles, displaced along their common diameter. The two semicircles can be considered to produce lifting effects. As a result, they are modelled by a collection of discrete vortices on their contours. The flow field is then governed by the Laplace equation. The versatile Neumann boundary condition, applied over the contour of the semicircles and the Kutta Joukowsky condition applied at the four extremities of the semicircles have been used in the modelling. The torque distribution of the stationary rotor and the unsteady pressure field on the blades of the rotating rotor, predicted by the code developed, have been compared and validated by some experimental data. © 2009.

Campbell B.C.V.,Royal Melbourne Hospital | Kleinig T.J.,Royal Adelaide Hospital | Dewey H.M.,Austin Health | Dewey H.M.,Monash University | And 33 more authors.
New England Journal of Medicine | Year: 2015

Background: Trials of endovascular therapy for ischemic stroke have produced variable results. We conducted this study to test whether more advanced imaging selection, recently developed devices, and earlier intervention improve outcomes. Methods: We randomly assigned patients with ischemic stroke who were receiving 0.9 mg of alteplase per kilogram of body weight less than 4.5 hours after the onset of ischemic stroke either to undergo endovascular thrombectomy with the Solitaire FR (Flow Restoration) stent retriever or to continue receiving alteplase alone. All the patients had occlusion of the internal carotid or middle cerebral artery and evidence of salvageable brain tissue and ischemic core of less than 70 ml on computed tomographic (CT) perfusion imaging. The coprimary outcomes were reperfusion at 24 hours and early neurologic improvement (.8-point reduction on the National Institutes of Health Stroke Scale or a score of 0 or 1 at day 3). Secondary outcomes included the functional score on the modified Rankin scale at 90 days. Results: The trial was stopped early because of efficacy after 70 patients had undergone randomization (35 patients in each group). The percentage of ischemic territory that had undergone reperfusion at 24 hours was greater in the endovascular-therapy group than in the alteplase-only group (median, 100% vs. 37%; P<0.001). Endovascular therapy, initiated at a median of 210 minutes after the onset of stroke, increased early neurologic improvement at 3 days (80% vs. 37%, P = 0.002) and improved the functional outcome at 90 days, with more patients achieving functional independence (score of 0 to 2 on the modified Rankin scale, 71% vs. 40%; P = 0.01). There were no significant differences in rates of death or symptomatic intracerebral hemorrhage. Conclusions: In patients with ischemic stroke with a proximal cerebral arterial occlusion and salvageable tissue on CT perfusion imaging, early thrombectomy with the Solitaire FR stent retriever, as compared with alteplase alone, improved reperfusion, early neurologic recovery, and functional outcome. (Funded by the Australian National Health and Medical Research Council and others; EXTEND-IA ClinicalTrials.gov number, NCT01492725, and Australian New Zealand Clinical Trials Registry number, ACTRN12611000969965.) Copyright © 2015 Massachusetts Medical Society.

Feki K.,University of Sfax | Quintero F.J.,Institute Recursos Naturales y Agrobiologia | Pardo J.M.,Institute Recursos Naturales y Agrobiologia | Masmoudi K.,University of Sfax
Plant Molecular Biology | Year: 2011

We have identified a plasma membrane Na+/H+ exchanger from durum wheat, designated TdSOS1. Heterologous expression of TdSOS1 in a yeast strain lacking endogenous Na+ efflux proteins showed complementation of the Na+- and Li+-sensitive phenotype by a mechanism involving cation efflux. Salt tolerance conferred by TdSOS1 was maximal when co-expressed with the Arabidopsis protein kinase complex SOS2/SOS3. In vitro phosphorylation of TdSOS1 with a hyperactive form of the Arabidopsis SOS2 kinase (T/DSOS2Δ308) showed the importance of two essential serine residues at the C-terminal hydrophilic tail (S1126, S1128). Mutation of these two serine residues to alanine decreased the phosphorylation of TdSOS1 by T/DSOS2Δ308 and prevented the activation of TdSOS1. In addition, deletion of the C-terminal domain of TdSOS1 encompassing serine residues at position 1126 and 1128 generated a hyperactive form that had maximal sodium exclusion activity independent from the regulatory SOS2/SOS3 complex. These results are consistent with the presence of an auto-inhibitory domain at the C-terminus of TdSOS1 that mediates the activation of TdSOS1 by the protein kinase SOS2. Expression of TdSOS1 mRNA in young seedlings of the durum wheat variety Om Rabia3, using different abiotic stresses (ionic and oxidative stress) at different times of exposure, was monitored by RT-PCR. © 2011 Springer Science+Business Media B.V.

Dhahri A.,University of Monastir | Dhahri J.,University of Monastir | Hlil E.K.,CNRS Neel Institute | Dhahri E.,University of Sfax
Journal of Alloys and Compounds | Year: 2012

We have studied the effect of Ti substitution on magnetic and magnetocaloric properties in La 0.57Nd 0.1Pb 0.33Mn 1-xTi xO 3 (x = 0.1 and x = 0.15) over a wide temperature range (T = 240-340 K). The prepared samples remain single phase and exhibit paramagnetic (PM)-ferromagnetic (FM) phase transition (T C) at 300 and 280 K for x = 0.1 and x = 0.15, respectively. From the magnetic measurements as function of temperature and magnetic applied field, we have discovered a large magnetic entropy change (-ΔS M) at Curie temperature.ΔS M has been deduced by two methods: Maxwell relation and Landau theory. The maximum value of the magnetic entropy change obtained from the M(H) curves and it increases with increase of Ti content from 4.85 J kg -1 K -1 at 299 K to 5.2 J kg -1 K -1 at 279 K, under ΔH = 5 T. The field dependence of the magnetic entropy change is also analyzed showing the power law dependence, ΔS M ∝ H n where n = 0.610(3) for x = 0.1 and n = 0.525(5) for x = 0.15 at their respective transition temperatures. The relative cooling power (RCP) and its field dependence are also analyzed. The obtained results show that La 0.57Nd 0.1Pb 0.33Mn 1-xTi xO 3 could be considered as a potential candidate for magnetic refrigeration applications around room temperature. © 2012 Published by Elsevier B.V.

Jarboui S.,University of Sfax | Forget P.,University of Quebec at Trois - Rivieres | Boujelbene Y.,University of Sfax
Public Transport | Year: 2012

The paper provides a literature review of public road transport efficiency. We classified 24 articles published between 2000 and 2011, based on journals, date of publication, the nature of the papers', the context of the study, the adopted approach by which efficiency is measured, the adopted outputs and inputs and empirical findings. Results are presented, discussed and future directions are generated. The classification scheme technique shows that the application of the mixed approach of Data Envelopment Analysis and Stochastic Frontier Analysis (DEA-SFA), with operators of different nationalities, is more robust for analysis of public transport efficiency, and for identifying sources inefficiency. Financial variables are important inputs and outputs for efficiency studies. However, although the frontier literature has substantially contributed to the knowledge of public transport technologies and the determinants of performance, it has been found that many important issues remain unresolved. © 2012 Springer-Verlag.

Baccour L.,University of Sfax | Alimi A.M.,University of Sfax | John R.I.,De Montfort University
Journal of Intelligent and Fuzzy Systems | Year: 2013

Intuitionistic fuzzy sets gained attention of many researchers and are employed in many axes of research. Thus, different operators are given to deal with intuitionistic fuzzy sets, among them similarity measures. The latter are the object of many propositions and discussions. Our aim is to present several studies on similarity measures between intuitionistic fuzzy sets. Such presentation is very important for different research topics such as pattern recognition, decision making and market prediction. © 2013-IOS Press and the authors. All rights reserved.

Tang V.,University of Sfax | Poon W.S.,University of Sfax | Kwan P.,Chinese University of Hong Kong | Kwan P.,Royal Melbourne Hospital
Neurology | Year: 2015

Objective: To investigate the effectiveness of mindfulness-based therapy (MT) and social support (SS) in patients with drug-resistant epilepsy. Methods: We performed an assessor-blinded randomized control trial. Sixty patients with drug-resistant epilepsy were randomly allocated to MT or SS (30 per group). Each group received 4 biweekly intervention sessions. The primary outcome was the change in the total score of the Patient-Weighted Quality of Life in Epilepsy Inventory (QOLIE-31-P). Secondary outcomes included seizure frequency, mood symptoms, and neurocognitive functions. The assessors were blinded to the patient's intervention grouping. Results were analyzed using general linear model with repeated measure. Results: Following intervention, both the MT (n 30) and SS (n 30) groups had an improved total QOLIE-31-P, with an improvement of +6.23 for MT (95% confidence interval [CI] +4.22 to +10.40) and +3.30 for SS (95% CI +1.03 to +5.58). Significantly more patients in the MT group had a clinically important improvement in QOLIE-31-P (+11.8 or above) compared to those who received SS (11 patients vs 4 patients). Significantly greater reduction in depressive and anxiety symptoms, seizure frequency, and improvement in delayed memory was observed in the MT group compared with the SS group. Conclusions: We found benefits of short-term psychotherapy on patients with drug-resistant epilepsy. Mindfulness therapy was associated with greater benefits than SS alone in quality of life, mood, seizure frequency, and verbal memory. Classification of evidence: This study provides Class II evidence that mindfulness-based therapy significantly improves quality of life in patients with drug-resistant epilepsy. © 2015 American Academy of Neurology.

Magrone T.,University of Sfax | Jirillo E.,University of Sfax
Endocrine, Metabolic and Immune Disorders - Drug Targets | Year: 2010

The continuous antigenic triggering has greatly contributed to the evolution of the immune system and, therefore, animals have developed cells able to cope with a broad variety of microbial antigens and or their toxins, e.g., endotoxins. At the same time, intestinal commensals have evolved along with human progress and introduction of new foods, thus empowering both regional and systemic immune response. In this review, some important steps in the evolution of the immune system will be analyzed such as organization of lymphoid organs, formation of germinal centers, leukocyte attraction to tissue, function of Toll like receptors and role of antimicrobial peptides. In particular, the major phylogenetic acquisitions of living organisms in the assessment of the immune machinery will be emphasized. Finally, fish will be taken into consideration as animal models of human diseases also in view of drug design strategies. Special attention will be focused on vaccinated salmon and zebrafish models. © 2010 Bentham Science Publishers Ltd.

Mhadhbi M.,University of Sfax | Khitouni M.,University of Sfax | Escoda L.,University of Girona | Sunol J.J.,University of Girona
Materials Letters | Year: 2010

The evolution of the microstructure of the mixture iron and aluminium powders during the high energy mechanical alloying process was investigated by X-ray line profile analysis. Analysis of line breadths was carried out to get an insight into the interrelated effects of grain size, lattice strain and dislocations. The final product of the MA process was the nanocrystalline Fe(Al) solid solution with a mean crystallite of 10 nm. On the basic on the modified Williamson-Hall plots, the root-mean squared strains were explained by the presence of dislocations, with a dislocation density of about 6 × 1016 m- 2. The identified steady-state saturation values of these parameters can be related to accumulate strain hardening of the powder material during longer milling times. © 2010 Elsevier B.V.

Khedri J.,University of Sfax
International Journal of Engineering and Technology | Year: 2015

This paper deals with the modelling, analysis design and experimental validation of a robust control method for a permanent magnet synchronous machine (PMSM) supplied with a PWM inverter based on a monovariable H infinity standard controller. Under the influence of uncertainties and external disturbances, by a variation of ±10% of all motor parameters from the nominal values, the robust performance control problem is formulated as a monovariable H infinity standard scheme and solved by a suboptimal iterative H infinity strategy. This new design method is able to ensure the stabilization of the augmented system formed of the perturbed system and weighting filters with improved performance in face of parameter variation and external disturbances. A Simulation and experimental study was carried out to illustrate the effectiveness of the proposed method.

Burazeri G.,Maastricht University | Burazeri G.,University of Sfax | Kark J.D.,Hebrew University of Jerusalem
Alcohol and Alcoholism | Year: 2010

Aims: To assess the prevalence and determinants of binge drinking in the middle-age population of transitional postcommunist Albania, for which data were previously unavailable. Methods: A population-based sample aged 35-74 years, interviewed and examined in Tirana in 2003-2006, included 450 men and 235 women for whom data on alcohol intake were collected (65.5% response). Multivariable-adjusted logistic regression was used to assess the association of drinking patterns with sociodemographic, socioeconomic and psychosocial characteristics and coronary risk factors. Results: Age-standardized to the 2005 census, 9.2% (95% confidence interval, CI = 6.5-11.9%) and 10.3% (95% CI = 7.4-13.1%) of men reported two to three or more annual episodes of drunkenness and hangovers, respectively. In women, the prevalence of both these markers of binging was 1.4% (95% CI = 0-3.1%). Among men, 8.9% (95% CI = 6.2-11.6%) reported drinking ≥60 g alcohol per session. In multivariable-adjusted models in men, binge drinking was related to low educational level (odds ratio, OR = 1.8, 95% CI = 1.0-3.3), financial loss in the pyramid collapse (OR = 1.6, 95% CI = 1.0-2.5) and religiosity (inversely) in both Muslims and Christians (OR = 0.2, 95% CI = 0.1-0.4). Conclusions: Among men in this transitional Southeast European country, social disadvantage and financial stress appear to promote alcohol abuse (which is rare in women), and traditionalism may be protective. © The Author 2010. Published by Oxford University Press on behalf of the Medical Council on Alcohol.

Melki T.,University of Sfax | Kallel N.,University of Sfax | Fontugne M.,CEA Saclay Nuclear Research Center
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2010

Benthic foraminifera were analyzed at high-resolution (millennial scale) along core MD84-641 (33°02′ N; 33°38′ E) recovered in the Eastern Mediterranean Sea and covering the last four climatic cycles. The succession of benthic foraminiferal assemblages shows that the decrease in oxygen content of eastern Mediterranean deep water was progressive for sapropels S8, S7, S6, S5, S4, and S3 and rapid for sapropels S10, S9 and S1. This suggests that climatic conditions conducing to the wet epochs associated with sapropels S8, S7, S6, S5, S4 and S3 were progressive, whereas they were rapid for sapropels S10, S9, and S1. However, hydrological conditions responsible for organic matter preservation events seem to be different from one sapropel to another. Benthic foraminifera did not disappear completely during sapropels S10, S8, S6, and S4, suggesting an episodic activation of deep-water convection and an instability of humid period. © 2010 Elsevier B.V. All rights reserved.

Mozaffari-Khosravi H.,University of Yazd | Nabizade L.,University of Yazd | Yassini-Ardakani S.M.,University of Sfax | Hadinedoushan H.,University of Yazd | Barzegar K.,University of Yazd
Journal of Clinical Psychopharmacology | Year: 2013

The correlation between vitamin D deficiency and depression has recently been put forward and resulted in controversial findings. The present study was conducted to find out the effect of 2 single injections of 150,000 and 300,000 IU of vitamin D on improving the depression in depressed patients with vitamin D deficiency.This clinical trial study was carried out during 2011-2012 in Yazd, Islamic Republic of Iran. A total of 120 patients who had a Beck Depression Inventory II score of 17+ and were affected with vitamin D deficiency were randomly assigned to 3 groups of 40. They included G300, G150, and NTG. G300 and G150 received an intramuscular single dose of 300,000 and 150,000 IU of vitamin D, respectively, and the NTG group received nothing. After 3 months of intervention, the depression state, serum vitamin D, calcium, phosphorus, and parathormone were measured.The median of serum vitamin D after intervention were 60.2, 54.6, and 28.2 nmol/L (P < 0.001) for the G300, G150, and NTG, respectively. Percentages of vitamin D deficiency after intervention were 18, 20, and 91.2 for the groups, respectively. The serum calcium mean showed a statistically significant increase in just the 2 test groups receiving vitamin D. There was only significant difference in mean of Beck Depression Inventory II test score between G300 and NTG (P = 0.003).The results of the study revealed that first, the correction of vitamin D deficiency improved the depression state, and second, a single injection dose of 300,000 IU of vitamin D was safe and more effective than a 150,000-IU dose. Copyright © 2013 Lippincott Williams & Wilkins.

Elloumi O.,Institute National Agronomique Of Tunisie | Elloumi O.,University of Sfax | Ghrab M.,University of Sfax | Kessentini H.,Institute National Agronomique Of Tunisie | Ben Mimoun M.,Institute National Agronomique Of Tunisie
Scientia Horticulturae | Year: 2013

Pistachios (Pistacia vera L.) are widely grown in the arid rainfed areas of Tunisia. However, pistachio production is still low with important variation between years. This study investigated the responses of pistachio trees to variable winter chilling and annual precipitation. It was carried out in an experimental orchard of Mateur, the most important Tunisian cultivar in central Tunisia (34°94'11″, 10°60'82″) for a period of twelve years from 1997 to 2008. Yield correlated poorly with precipitation (varying on the range of 80-300. mm/year during the 12 years) and showed a moderate alternate bearing index of 0.63. However, flowering and nut yield of pistachio trees was a function of chill accumulation computed as chilling hours (CH), chill units (CU) or chilling portions (CP) depending on using Crossa-Raynaud, Utah or Dynamic models, respectively. For Mateur cultivar, the threshold chilling accumulation appeared to be 206 CH, 539 CU or 36 CP depending on the model used. Under this level, pistachio production was clearly affected. Warm winters with low chilling caused erratic floral bud break, delayed flowering, sparse foliage and decreased yield. With inadequate winter chilling, chemical treatments with hydrogen cyanamide (Dormex) at 2 and 4% increased floral bud break, advanced flowering period and improved vegetative growth of pistachio trees in comparison to the untreated control. As a conclusion, better prediction of chill accumulation must be achieved in the warm production region of Tunisia. To that effect, the Dynamic model showed the lowest coefficient of variation compared to the chilling hours and Utah models and seemed to better reflect what is happening on the field under our warm winter regions. © 2013 Elsevier B.V.

Ahram M.,University of Sfax | Othman A.,University of Jordan | Shahrouri M.,King Hussein Institute for Biotechnology and Cancer | Mustafa E.,University of Sfax
European Journal of Human Genetics | Year: 2014

A diversity of public participation in biobanking is a highlight for the success of biobanks. It was previously reported that only two-thirds of Jordanians expressed interest in biobanking. To promote public involvement in a biobank, it is imperative to determine the aspects that influence the decision-making to participate. On the basis of a national survey involving 3196 respondents, the influence of 13 biobanking factors was assessed, including returning research results, privacy, freedom of choice, uncertainties about research, monetary and health considerations, and personal belief. Perception toward each factor was also correlated with willingness to participate in a biobank. A considerable number of respondents indicated returning research results as influential in their decision to become biobank donors. Interestingly, whereas the positive perception of availability of general results (39%) correlated with willingness to donate for biobanking, the negative view of unavailability of individualized results (47%) did not correlate with unwillingness. Religious permission of sample donation for research had the strongest positive influence (61%) and the highest correlation to participate among positively perceived factors. Unspecified research was highly indicated as a negative factor (45%), but did not correlate with unwillingness to become a biobank donor, whereas allowed withdrawal had a positive effect (31%) and correlation to contribute to biobanking. The negative perception of accessing medical information (9.5%) and re-contact (8.5%) had the strongest correlation with unwillingness to donate to a biobank. These results may provide an insight into how to formulate strategies to promote public participation in biomedical research and biobanking. © 2014 Macmillan Publishers Limited.

Araujo R.,University of Porto | Araujo R.,University of Sfax | Amorim A.,University of Porto | Gusmao L.,University of Porto
Medical Mycology | Year: 2010

Environmental isolates of Aspergillus fumigatus are less studied than those recovered from clinical sources. In the present study, the genetic diversity among such environmental isolates was assessed, as well as their dispersion ability and the acquisition of new strains in 19 medical units of the same hospital. A. fumigatus isolates were genotyped using a single multiplex PCR-based reaction with eight microsatellite markers and an insertion/deletion polymorphism. A total of 130 unique genotypes were found among a total of 250 A. fumigatus isolates. Genotypic diversity ranged from 0.86 to 1 in samples from hospital rooms, and there was no correlation between these samples and the presence of high-efficiency particulate air filters or any other air filtration system. Four of the six most prevalent A. fumigatus strains were recovered from water samples. The occurrence of microvariation was common among environmental isolates, which affected each of the microsatellite markers. The assessment of the genetic diversity of A. fumigatus is a useful tool for illustrating the presence or absence of specific clonal populations in a clinical setting. A. fumigatus populations were highly dynamic indoors, and new populations were found in just a few months. Due to the high indoor dispersion capability of A. fumigatus, more attention should be given to strains with increased pathogenic potential or reduced susceptibility to anti-fungal drugs. © 2010 ISHAM.

Ben Halima N.,University of Sfax
RSC Advances | Year: 2016

Poly(vinyl alcohol) (PVA) is a water soluble synthetic polymer, with a backbone composed only of carbon atoms and is biodegradable under both aerobic and anaerobic conditions. This polymer can be prepared by the hydrolysis of polyvinylacetate and is one of the most important synthetic polymers used in commercial, industrial, medical and nutraceutical applications. The environmental issues caused by PVA industrial practice have increased globally. Several methods have been used to treat PVA industrial discharge including in particular physicochemical methods such as electrocoagulation. Nowadays, use of bioremediation for PVA release, which has caused serious pollution problems in the natural environment, has attracted much interest. The bioremediation ability of microorganisms and their PVA degrading enzymes, especially PVA oxidases/hydrolases, has long been perceived. These enzymes as well as symbiotic microorganisms could be an effective means for biodegradation of PVA. © The Royal Society of Chemistry 2016.

Samet Y.,University of Sfax | Agengui L.,University of Sfax | Abdelhedi R.,University of Sfax
Chemical Engineering Journal | Year: 2010

Laboratory experiments were carried out on the kinetic of the electrochemical degradation of aqueous solutions containing chlorpyrifos as model compounds of organophosphorus pesticides. The process was studied under galvanostatic polarization mode in acidic medium using boron-doped diamond (BDD) anodes and graphite carbon bar as cathode. The chemical oxygen demand (COD) measurement during the processing permitted the evaluation of the kinetic of organic matter decay and the instantaneous current efficiency. The results showed that the degradation of this pesticide is dependent on its initial concentration, current density and temperature. COD decay follows a pseudo first-order kinetic and the process was under mass transport control within the range studied, regardless of the experimental conditions. The removal rate of COD increases with applied current density until 20mAcm-2 and decreases for higher values. The degradation rate increased significantly with increasing temperature and initial concentration of chlorpyrifos. The best obtained conditions for COD removal on the BDD anode to degrade chlorpyrifos solutions (COD(0) = 456mgL-1) include operating at 20mAcm-2 and 70 °C. This arrangement allows to completely degrade chlorpyrifos in just 6 h. Compared with PbO2, BDD anode has shown more performance and rapidity in the COD removal in the same electrolysis device. © 2010 Elsevier B.V.

Athmania D.,University of Tébessa | Achour H.,University of Sfax
Remote Sensing | Year: 2014

Digital Elevation Models (DEMs) including Advanced Spaceborne Thermal Emission and Reflection Radiometer-Global Digital Elevation Model (ASTER GDEM), Shuttle Radar Topography Mission (SRTM), and Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010) are freely available for nearly the entire earth's surface. DEMs that are usually subject to errors need to be evaluated using reference elevation data of higher accuracy. This work was performed to assess the vertical accuracy of the ASTER GDEM version 2, (ASTER GDEM2), the Consultative Group on International Agriculture Research-Consortium for Spatial Information (CGIAR-CSI) SRTM version 4.1 (SRTM v4.1) and the systematic subsample GMTED2010, at their original spatial resolution, using Global Navigation Satellite Systems (GNSS) validation points. Two test sites, the Anaguid Saharan platform in southern Tunisia and the Tebessa basin in north eastern Algeria, were chosen for accuracy assessment of the above mentioned DEMs, based on geostatistical and statistical measurements. Within the geostatistical approach, empirical variograms of each DEM were compared with those of the GPS validation points. Statistical measures were computed from the elevation differences between the DEM pixel value and the corresponding GPS point. For each DEM, a Root Mean Square Error (RMSE) was determined for model validation. In addition, statistical tools such as frequency histograms and Q-Q plots were used to evaluate error distributions in each DEM. The results indicate that the vertical accuracy of SRTM model is much higher than ASTER GDEM2 and GMTED2010 for both sites. In Anaguid test site, the vertical accuracy of SRTM is estimated 3.6 m (in terms of RMSE) 5.3 m and 4.5 m for the ASTERGDEM2 and GMTED2010 DEMs, respectively. In Tebessa test site, the overall vertical accuracy shows a RMSE of 9.8 m, 8.3 m and 9.6 m for ASTER GDEM 2, SRTM and GMTED2010 DEM, respectively. This work is the first study to report the lower accuracy of ASTER GDEM2 compared to the GMTED2010 data. © 2014 by the authors.

Kacem A.,University of Sfax | Krichen A.,University of Sfax | Manach P.-Y.,University of Southern Brittany
Journal of Materials Processing Technology | Year: 2011

The effect of the clearance-thickness ratio on the hole-flanging process was investigated to determine the occurrence of ironing. A 2 mm thick 1000 series aluminium alloy sheet was considered. An elastic-plastic finite element model using remeshing option was developed. Experiments were conducted to verify the reliability of the developed finite element model. A critical clearance-thickness ratio which is a limit between two conditions of hole-flanging was found: hole-flanging with edge stretching and hole-flanging with ironing in which the metal is squeezed between the punch and the die. The effect of the hole-flanging condition on the punch load, the forming kinematics, the flange geometry and the boring quality was studied. The finite element results were validated by experimental results. © 2011 Elsevier B.V. All rights reserved.

Ben Amor I.,University of Sfax | Arous M.,University of Sfax | Kallel A.,University of Sfax
Journal of Electrostatics | Year: 2014

The use of short palm tree lignocellulosic fibers as a reinforcing phase in polyester matrix has been reported. In order to improve interfacial adhesion, the esterification of the lignocellulosic filler in alkaline medium was performed using maleic anhydride. The dynamic dielectrical analysis of short palm tree lignocellulosic fibres reinforced polyester composites was carried out. Measurements were performed in the frequency range 1-104Hz. Two relaxations processes were identified in the case of polyester matrix and non treated fibre composite, which are the α relaxation associated with glass-rubbery transition of the polymer and the relaxation process associated with conductivity occurring as a result of the carriers charges diffusion for high temperature above glass transition and low frequencies.For the treated fiber composite with anhydride, a new relaxation process due to the molecular motion of amorphous celluloses was identified. © 2014 Elsevier B.V.

Farza M.,University of Caen Lower Normandy | M'Saad M.,University of Caen Lower Normandy | Triki M.,University of Caen Lower Normandy | Triki M.,University of Sfax | Maatoug T.,University of Sfax
Systems and Control Letters | Year: 2011

This paper presents a high gain observer for a class of MIMO nonlinear systems involving some uncertainties. The latter is particularly composed of cascade subsystems where each subsystem is associated with a subset of the output variables, and assumes a triangular dependence on its own state variables and may depend on the state variables of all other subsystems. The main contribution consists in extending the available results to allow more interconnections between the subsystems. Of fundamental interest, it is shown that the underlying observation error exponentially converges to zero in the absence of uncertainties. Moreover, the observation error can be made as small as desired by properly specifying the observer design parameter in the case where uncertainties are considered. © 2010 Elsevier B.V. All rights reserved.

Kammoun I.,University of Sfax | Cipriano A.M.,Thales Alenia
IEEE Transactions on Wireless Communications | Year: 2011

The use of single-antenna terminals for coherent cooperative wireless communications has received more attention in literature than for non-coherent communications. But acquiring knowledge of the fading coefficients in a cooperative scheme is very challenging in a fast fading case. In this paper, we develop several cooperative schemes suited for systems which do not require channel state information at either relays or destination. We analyze the performance of these schemes in terms of diversity gain and error probability. The diversity gained with an equal gain combiner at the destination is investigated too. The proposed cooperative schemes are compared to the literature and are shown to achieve significant performance gain depending on the type of relaying protocol. © 2011 IEEE.

A new experimental procedure is proposed which uses the Scanning Electron Microscope Mirror Effect (SEMME) for the dynamic investigation of charge trapping in insulating materials. This experimental procedure allows to the mirror method which is usually described as static to be considered as dynamic. The dynamic trapping properties of the polymethyl-methacrylate (PMMA) polymer material are investigated and the time constants of charge processes are evaluated for various accelerating voltages. The experimental results reveal that the values of trapped charge at steady state obtained by the proposed procedure are in good agreement with these obtained using the electrostatic influence method (EIM) under the identical experimental conditions of electron irradiation. © 2013 .

Jamal W.,University of Sfax | Shahin M.,University of Sfax | Rotimi V.O.,University of Sfax
Anaerobe | Year: 2010

The susceptibility trends for all anaerobes processed by the Anaerobe Reference Laboratory against various antibiotics were determined by using data for 2557 isolates referred by all government hospitals in Kuwait from 2002 to 2007. MIC were determined for the following anti-anaerobic antibiotics: amoxicillin-clavulanic acid, clindamycin, imipenem, meropenem, metronidazole, penicillin, piperacillin, piperacillin-tazobactam and vancomycin (for Gram-positive anaerobes only), using E-test method. The commonest isolates were Bacteroides fragilis (36.8%), followed by Peptostreptococcus spp. (21.9%), Bacteroides ovatus (15.5%) and Prevotella bivia (12.1%). In addition, Prevotella oralis and other Bacteroides spp. represented 8.5% and 8.1% of total number of isolates, respectively. Resistance rate varied among the antimicrobial agents and the species tested. The β-lactams, with the exception of penicillin, were the most active drugs. Piperacillin-tazobactam was the only antimicrobial agent to which all the isolates were uniformly susceptible. Imipenem and metronidazole were highly active with resistance rate of only <5% recorded against most isolates. However, 42.8, 55.8 and 9.3% of Clostridium difficile isolates were resistant to imipenem, clindamycin and meropenem, respectively. It is noteworthy that from 2002 to 2007, there was a gradual increase in resistance rates to clindamycin, amoxicillin-clavulanic acid and piperacillin among B. fragilis. Periodic surveillance of antibiotic resistance among the anaerobic bacteria is recommended as a guide to empiric antibiotic use and formulation of guideline for appropriate choice of antimicrobial therapy in anaerobic infections. © 2009 Elsevier Ltd.

Kasule O.H.,University of Sfax
Journal of Taibah University Medical Sciences | Year: 2013

The paper discusses various issues related to assessment in the context of the Arab world and focusing on 2 forms of assessment: multiple choice questions (MCQs) and objective structured clinical examinations (OSCEs). The appropriate assessment system is determined by the content and method of teaching as well as the expected knowledge and skills of the final product, the health professional. Assessment motivates students to study hard. It is also used to make decisions on promotion of students. A good assessment system cannot be imported; it must be home grown taking into consideration the cultural, linguistic, and educational background of the students. Centralized assessment not under the immediate control of teachers in contact with the students is appropriate for standardized examinations like the United States Medical Licensure Examination (USMLE) but is associated with many challenges in internal examinations within the teaching institution: complicated logistics, marginalization of the teachers, and the injustice of treating un-equals as equals. Assessment covers the two components of medicine: the science and the art (practical). The MCQ format assesses knowledge and its applications. The OSCE format assesses practical skills. Writing good MCQ items takes a lot of effort and time to review but is easy to administer and score. The OSCE based on simulated patients (SP) has ably replaced the traditional long and short clinical cases but penalizes the advanced candidate who asks the SP questions off the script. I propose using SPs who actually had personal experience of the condition being tested. I also propose some items in the OSCE that are of critical knowledge for professionals and which should have higher scores assigned to them. Students should be failed in the whole examination if they do not know some of these critical items. © 2013 Taibah University. Production and hosting by Elsevier Ltd. All rights reserved.

Zribi N.,University of Sfax | Feki Chakroun N.,University of Sfax | Bahloul A.,Habib Bourguiba Hospital | Ammar Keskes L.,University of Sfax
Fertility and Sterility | Year: 2010

Objective: To evaluate the effect of cryopreservation on sperm motility and viability and to assess sperm DNA fragmentation and oxidation in men undergoing infertility investigation before and after cryopreservation in liquid nitrogen. Design: Analysis of cryopreservation effects on sperm DNA integrity. Setting: Laboratory of Histology-Embryology of medicine faculty, Sfax, Tunisia. Patient(s): Fifteen semen samples from men undergoing infertility investigation. Intervention(s): Neat semen samples were cryopreserved in liquid nitrogen using a commercial freezing medium (SpermFreeze, Fertipro, Belgium) according to the manufacturer's instructions. Samples were thawed at room temperature. Main Outcome Measure(s): Sperm DNA fragmentation was assessed using terminal deoxynucleotidyl transferase (Tdt) mediated dUTP nick end labeling and sperm DNA oxidation was determined using a fluorescent assay (OxyDNA test) for the detection of 8-oxoguanine. Evaluation of DNA fragmentation and oxidation rates was carried out before and after cryopreservation using flow cytometry. Result(s): A significant decrease in sperm motility and viability was observed after cryostorage. In addition, sperm DNA fragmentation and DNA oxidative damage increased significantly after cryopreservation/thaw. Conclusion(s): Cryopreservation has deleterious effects on sperm DNA by inducing DNA fragmentation and oxidation but the mechanisms underlying such damages need to be elucidated by further investigations. © 2010 American Society for Reproductive Medicine.

Kasule O.H.,University of Sfax
Journal of Taibah University Medical Sciences | Year: 2013

Objective: This paper identified ethical issues relating to brain death and analyzed them according to the purposes of the Law, maqasid al shari'at, and principles of the law, qawa'id al fiqh, to reach conclusions of practical importance. Methods: Issues arising in brain death were selected from articles retrieved from PUBMED over a 10-year period. Practical and conceptual issues identified in the articles were analyzed using maqasid al shari'atand qawa'id al fiqh. Results: Early determination of death by use of brain death criteria was motivated by the need to harvest transplantation organs earlier, to save intensive care resources by earlier cessation of life support, and to obtain tissues for research before deterioration. These motives would violate the principle of intention which requires that actions be judged by underlying intentions and that the end does not justify the means. In this case the nobility of the ends and their public interest were overriding considerations. The requirements, by the principle of certainty, of evidence-based proof of death were partially fulfilled by brain death criteria, tests, and examinations. The principle of custom was partially fulfilled because there was no universal consensus on criteria of brain death; the criteria varied by country, by institution, and over time. Conclusions and recommendations: Brain stem death, determined by clinical examination with or without instrumental confirmation, should remain the mainstay of death definition. Legal rulings on brain death should be reviewed every 3 years to take into consideration new developments in medical knowledge and technology. © 2013 Taibah University. Production and hosting by Elsevier Ltd. All rights reserved.

Finley C.J.,University of Sfax | Kondra J.,University of Sfax | Clifton J.,University of Sfax | Yee J.,University of Sfax | Finley R.,University of Sfax
Annals of Thoracic Surgery | Year: 2010

Background: Our objective is to ascertain if preoperative and perioperative treatments affect the short- and long-term symptom frequency or symptom scores for dysphagia, regurgitation, and heartburn in patients with laparoscopic Heller myotomy for achalasia. Methods: From 1994 to 2008, 261 patients undergoing laparoscopic esophageal myotomy were enrolled prospectively. The diagnosis of classic achalasia was made on clinical history, barium swallow, endoscopy, and manometry. A validated symptom questionnaire and history was taken for each patient at the preoperative visit and at each postoperative visit. Results: In all, 261 patients had laparoscopic Heller myotomy during the study period. Preoperatively, 137 patients (62.3%) tried medications, 101 (38.7%) were treated with pneumatic dilation, and 29 (11.1%) were treated initially with at least one injection of botulinum toxin into the lower esophageal sphincter. In all, 134 patients (51.3%) received a Dor anterior fundoplication. On multivariate regression controlling for age and sex, preoperative dilation (p = 0.031), injection of botulinum toxin (p = 0.044), and a fundoplication (p = 0.005) were associated with significantly worse early postoperative dysphagia, with odds ratios of 2.11, 2.56, and 2.80, respectively; previous botulinum toxin injection was associated with worse late postoperative dysphagia (p = 0.001), regurgitation (p = 0.031), and heartburn (p = 0.049), with odds ratios of 5.24, 2.87, and 2.52, respectively. There was a trend for no fundoplication to be associated with late postoperative heartburn (p = 0.077) with an odds ratio of 1.80. Conclusions: Many patients presenting for Heller myotomy have previously undergone a different form of treatment. Early postoperative dysphagia was affected by dilation, botulinum toxin injection, and fundoplication. Only botulinum toxin injection was associated with late symptoms. © 2010 The Society of Thoracic Surgeons.

Graeber M.B.,University of Sfax | Graeber M.B.,University of Sydney | Streit W.J.,University of Florida
Acta Neuropathologica | Year: 2010

The past 20 years have seen a gain in knowledge on microglia biology and microglia functions in disease that exceeds the expectations formulated when the microglia "immune network" was introduced. More than 10,000 articles have been published during this time. Important new research avenues of clinical importance have opened up such as the role of microglia in pain and in brain tumors. New controversies have also emerged such as the question of whether microglia are active or reactive players in neurodegenerative disease conditions, or whether they may be victims themselves. Premature commercial interests may be responsible for some of the confusion that currently surrounds microglia in both the Alzheimer and Parkinson's disease research fields. A critical review of the literature shows that the concept of "(micro)glial inflammation" is still open to interpretation, despite a prevailing slant towards a negative meaning. Perhaps the most exciting foreseeable development concerns research on the role of microglia in synaptic plasticity, which is expected to yield an answer to the question whether microglia are the brain's electricians. This review provides an analysis of the latest developments in the microglia field. © 2009 Springer-Verlag.

Triki I.,University of Sfax | Zairi M.,University of Sfax | Ben Dhia H.,University of Sfax
Water and Environment Journal | Year: 2013

In many developing countries, the groundwater monitoring network is randomly designed, and consequently needs to be revised and optimised to reduce operation time and cost, remove redundant piezometric data, and strengthen sparseness data zone with supplementary observation well. The geostatistical approach used in this work is based on the universal kriging variance combined with cross-validation test. Hence, a rational interpolation of water table elevations was performed to evaluate the accuracy of data employed in the piezometric head modelling. In this study, the groundwater monitoring network of the Sfax superficial aquifer in the south east of Tunisia was optimised. The elimination of five observation wells induces the invariability in the variance of estimate due to their less contribution in interpretations of the groundwater level behaviour. However, 38 wells were added at areas of high variance of the kriging in order to ameliorate the spatial coverage of the monitoring network. © 2012 CIWEM.

Kasule O.H.,University of Sfax
Journal of Taibah University Medical Sciences | Year: 2013

Professionalism is defined as behaviors and attitudes. The American Board of Internal Medicine (ABIM) listed 6 dimensions of good professionalism as: altruism, accountability, excellence, duty, honor and integrity, and respect for others; and listed elements that erode professionalism: abuse of power and sexual harassment, conflicts of interest, professional arrogance, physician impairment, and fraud in research. The formulation of professionalism from an Islamic perspective consists of 7 dimensions: (faith (iman), consciousness (taqwat), best character (ahsan al akhlaq), excellent performance (itqaan al 'amal), strife toward perfection (ihsan), responsibility (amanat), and self-accountability (muhasabat al nafs). From the earliest human history medical practice was by non-professionals, members of the family and religious leaders. Development of scientific medicine and its technology required training of dedicated professionals who had specialized skills and had to follow codes of professionalism. Professional organizations were set up to defend the rights of members, regulate and discipline practitioners, regulate training, and promote scientific research and exchange. Professionalism is taught actively as structured curriculum courses or passively as apprenticeship under good role models. Various approaches are used in the assessment of professionalism such as using special instruments like the Nijmegen Professional Scale developed in the Netherlands and the Professional Mini Evaluation instrument developed in Canada. Professionalism can also be assessed by (a) assessing knowledge, attitudes, and practice of professionalism; peer assessment of professionalism, (b) assessment of student behaviors such as fulfilling duties, and (c) analysis of student narratives on critical incidents. © 2013 Taibah University.

Nanocomposite hydrogels based on cellulose nanofibrils (CNFs) and poly(acrylic acid-co-acrylamide) were synthesized via in situ free radical polymerization in an aqueous suspension of CNFs. Effects of the inclusion of CNFs with content up to 10 wt% on the swelling properties at different pH and on the compression strength were investigated. The presence of CNFs was shown to strongly reinforce the hydrogel without deteriorating its elasticity. Nanocomposite hydrogel with a content of 10 % CNF supported respectively a strength and deformation about 13 and 2 times higher than that of the neat hydrogel. This effect was explained by the grafting of polymers on the CNFs surface, contributing to an increase in the effective crosslinking density, and improving the interfacial adhesion between polymer chains and CNFs. Moreover, the addition of CNF enhanced the water holding capacity of the hydrogel and caused the system to release urea simulating a fertilizer in a more controlled manner than that with neat hydrogel. © 2016 Springer Science+Business Media Dordrecht

N-acetylcysteine belongs to commonly used drugs from expectorants. Its mechanism of action is not based on the modified mucus formation and/or its structure in airways only, however, it possesses also antioxidant or immunomodulatory properties. These activities are discussed here in the context of its current therapeutic use with a special focus on paediatric population. © 2014.

Lucas M.G.,Morriston Hospital | Bosch R.J.L.,UMC Utrecht | Burkhard F.C.,University of Bern | Cruz F.,University of Sfax | And 7 more authors.
European Urology | Year: 2012

Context: The European Association of Urology (EAU) guidelines on urinary incontinence published in March 2012 have been rewritten based on an independent systematic review carried out by the EAU guidelines panel using a sustainable methodology. Objective: We present a short version here of the full guidelines on the surgical treatment of patients with urinary incontinence, with the aim of dissemination to a wider audience. Evidence acquisition: Evidence appraisal included a pragmatic review of existing systematic reviews and independent new literature searches based on Population, Intervention, Comparator, Outcome (PICO) questions. The appraisal of papers was carried out by an international panel of experts, who also collaborated in a series of consensus discussions, to develop concise structured evidence summaries and action-based recommendations using a modified Oxford system. Evidence summary: The full version of the guidance is available online (www.uroweb.org/guidelines/online-guidelines/). The guidance includes algorithms that refer the reader back to the supporting evidence and have greater accessibility in daily clinical practice. Two original meta-analyses were carried out specifically for these guidelines and are included in this report. Conclusions: These new guidelines present an up-to-date summary of the available evidence, together with clear clinical algorithms and action-based recommendations based on the best available evidence. Where high-level evidence is lacking, they present a consensus of expert panel opinion. © 2012 European Association of Urology.

Background: The survival of patients with a metastatic colon cancer has improved with palliative chemotherapy, targeted therapies and surgery. Several prognostic factors influencing the survival of these patients were identified in the literature represented mainly by clinical factors: general condition, number and site of metastases, rate of white blood cells, initial carcinoembryonic antigen (CEA) rate, hemoglobin level, and therapeutic factors mainly represented by resection of metastases. Aim: To evaluate within a Tunisian retrospective study the significant prognostic factors on survival of metastatic colorectal cancer (MCRC). Methods: We collected retrospectively 130 patients with MCRC treated in Sfax from january 2000 to December 2007. Uni and multivariate analysis were performed according to cox model for the following factors: Age or > 40 years, gender, synchronous vs metachronous metastases, disease-free survival (DFI) 1 > 1year, tumor site(colon vs rectum), performance status or PS (0-1or 2-3), white blood cells count (< or > 103/ml3, haemoglobin rate (Hb) or > 11g/dl, seric carcinoembryonic antigen rate (CEA) < vs > 10 ng/ml, number of metastatic sites (single vs multiple), site of metastatic site (liver vs extrahepatic) and resection or not of the metastatic localizations. Results: Statistical analysis showed for univariate analysis the positive impact of: PS ≤ 1, (Hb) rate > 11 g/dl, CEA) < 10 ng/ml and resection of metastases, while in in multivariate analysis, they were: a good PS and Hb > 11 g/dl. Conclusion: Our retrospective study confirmed the known prognostic impact of simple clinical tools like a good performance Status and Hb > 11 g/dl, a (CEA) rate lower than 10 ng/ml and resection of metastases which were identified by several other series such as predictive factors of a better survival in patients with metastatic colorectal cancer. © 2015 Tunisie Medicale All rights received.

Bouaziz S.,University of Sfax | Dhahri H.,University of Sfax | Alimi A.M.,University of Sfax | Abraham A.,VSB - Technical University of Ostrava | Abraham A.,Network Intelligence
Neurocomputing | Year: 2013

In this paper, a tree-based encoding method is introduced to represent the Beta basis function neural network. The proposed model called Flexible Beta Basis Function Neural Tree (FBBFNT) can be created and optimized based on the predefined Beta operator sets. A hybrid learning algorithm is used to evolving FBBFNT Model: the structure is developed using the Extended Genetic Programming (EGP) and the Beta parameters and connected weights are optimized by the Opposite-based Particle Swarm Optimization algorithm (OPSO). The performance of the proposed method is evaluated for benchmark problems drawn from control system and time series prediction area and is compared with those of related methods. © 2013 Elsevier B.V.

Kanoun S.,University of Sfax | Alimi A.M.,University of Sfax | Lecourtier Y.,University of Rouen
IEEE Transactions on Systems, Man, and Cybernetics, Part B: Cybernetics | Year: 2011

In this paper, we propose a new linguistic-based approach called the affixal approach for Arabic word and text image recognition. Most of the existing works in the field integrate the knowledge of the Arabic language in the recognition process in two ways: either in post-recognition using the language of dictionary (dictionary of words) to validate the word hypotheses suggested by the OCR or in the course of the recognition process (recognition directed by a lexicon) using a statistical model of the language (Hidden Markov Model or N-gram). The proposed approach uses the linguistic concepts of the vocabulary to direct and simplify the recognition process. The principal contribution of the proposed approach is to be able to categorize the word hypotheses in words that are either derived or not derived from roots and to characterize morphologically each word hypothesis in order to prepare the text hypotheses for later analyses (for example, syntactic analysis; to filter the sentence hypotheses). © 2006 IEEE.

Municipal Solid Waste (MSW) collection is a necessary process in any municipality resulting in the quality-of-life, economic aspects and urban structuralization. The intrinsic nature of MSW collection relates to the development of effective vehicle routing models that optimize the total traveling distances of vehicles, the environmental emission and the investment costs. In this article, we propose a generalized vehicle routing model including multiple transfer stations, gather sites and inhomogeneous vehicles in time windows for MSW collection. It takes into account traveling in one-way routes, the number of vehicles per m2 and waiting time at traffic stops for reduction of operational time. The proposed model could be used for scenarios having similar node structures and vehicles' characteristics. A case study at Danang city, Vietnam is given to illustrate the applicability of this model. The experimental results have clearly shown that the new model reduces both total traveling distances and operational hours of vehicles in comparison with those of practical scenarios. Optimal routes of vehicles on streets and markets at Danang are given. Those results are significant to practitioners and local policy makers. © 2016 Elsevier Ltd.

Masmoudi M.,University of Sfax | El Badsi B.,University of Sfax | Masmoudi A.,University of Sfax
IEEE Transactions on Industry Applications | Year: 2014

Currently, road vehicles are more equipped with permanent magnet synchronous motors. Particularly interesting are brushless dc (BLDC) motors, which, due to their inherently sensorless operation, are considered as viable candidates in large-scale production industries such as the automotive one. Within this trend, this paper deals with the synthesis and implementation of a novel direct torque control (DTC) strategy dedicated to the control of BLDC motor drives. Compared with the most recent and highly performed DTC strategy, the proposed one offers improved reliability due to the achievement of balanced switching frequencies of the inverter upper and lower insulated-gate bipolar transistors, on one hand, and the reduction in the average value of the motor common mode voltage, on the other hand. Furthermore, the torque ripple is significantly damped during sector-to-sector commutations using a three-level hysteresis torque controller. An experientially based comparative study of the most recent and highly performed DTC strategy from one side and the introduced one from the other side clearly highlights the potentialities exhibited by the latest one. © 1972-2012 IEEE.

Trigui M.,University of Sfax | Hsouna A.B.,University of Sfax | Tounsi S.,University of Sfax | Jaoua S.,University of Sfax
Industrial Crops and Products | Year: 2013

In the present study, we evaluated in vitro antimicrobial and antioxidant properties of Thymelaea hirsuta extracts as well as its phytochemical composition. Total phenolic and flavonoid contents were highest in acetone and ethyl acetate extracts respectively. The different extracts were tested against a panel of microorgani