Réduction de la luxation de la tête radiale dans le cadre de la maladie exostosante: à propos d’un cas

La luxation de la tête radiale dans le cadre de la maladie exostosante  constitue une complication de déséquilibre de croissance des deux os del'avant bras secondaire à une exostose distale de l'ulna. Le traitement est difficile et controversé par les auteurs. Nous présentons une technique originale pour le traitement de cette entité. Après la correction de l'index radio-cubital inférieur par un allongement progressif de l'ulna, une fixation radio-cubitale inférieure par les fiches distales de l'Orthofix® et un deuxième allongement de l'ulna permet l'abaissement de la tête radiale et sa réduction. La réduction progressive par allongement de l'ulna par la méthode de callotasis constitue une technique séduisante et réalise l'inverse du ce qui passé lors de ralentissement de croissance de l'ulna sous l'effet de l'exostose ulnaire

Molecular study of the perforin gene in familial hematological malignancies

Perforin gene (PRF1) mutations have been identified in some patients diagnosed with the familial form of hemophagocytic lymphohistiocytosis (HLH) and in patients with lymphoma. The aim of the present study was to determine whether patients with a familial aggregation of hematological malignancies harbor germline perforin gene mutations. For this purpose, 81 unrelated families from Tunisia and France with aggregated hematological malignancies were investigated. The variants detected in the PRF1 coding region amounted to 3.7% (3/81). Two of the three variants identified were previously described: the p.Ala91Val pathogenic mutation and the p.Asn252Ser polymorphism. A new p.Ala 211Val missense substitution was identified in two related Tunisian patients. In order to assess the pathogenicity of this new variation, bioinformatic tools were used to predict its effects on the perforin protein structure and at the mRNA level. The segregation of the mutant allele was studied in the family of interest and a control population was screened. The fact that this variant was not found to occur in 200 control chromosomes suggests that it may be pathogenic. However, overexpression of mutated PRF1 in rat basophilic leukemia cells did not affect the lytic function of perforin differently from the wild type protein

Cross-tolerance to abiotic stresses in halophytes: Application for phytoremediation of organic pollutants

International audienceHalopytes are plants able to tolerate high salt concentrations but no clear definition was retained for them. In literature, there are more studies that showed salt-enhanced tolerance to other abiotic stresses compared to investigations that found enhanced salt tolerance by other abiotic stresses in halophytes. The phenomenon by which a plant resistance to a stress induces resistance to another is referred to as cross-tolerance. In this work, we reviewed cross-tolerance in halophytes at the physiological, biochemical, and molecular levels. A special attention was accorded to the cross-tolerance between salinity and organic pollutants that could allow halophytes a higher potential of xenobiotic phytoremediation in comparison with glycophytes

Déformations compressives d'âge pléistocène moyen à supérieur liées à la géométrie de failles décrochantes près d'Aïn es Semda (Tunisie centrale)

Middle to Upper Pleistocene Quaternary deformations linked to strike faults geometry near Aïn es Semda (Central Tunisia). The major NW-SE Ksour fault which limit the Sra Ouertane plateau from the down thrown graben of Ksour -North Rohia, is actually composed of many faulted kilometric segments. At Aïn es Semda (seven kilometres to the SW of Ksour city), the strike of the fault changes abruptly from N 160 to N 130. There, Middle to Upper Pleistocene beds are brought against Cretaceous series. During the Upper Miocene to Pleistocene NW -SE compression, this accident is reactived as a dextral slip-fault. The abrupt change in strike of this dextral slip-fault near Aïn es Semda is responsible of the local compressive deformations. The Quaternary deformed series on the border of the major strike-slip fault where it bends to become more orthogonal to the regional compressive stress show, on a small scale, some strike-slip faults with reverse components forming «pop up structures».L'accident de Ksour de direction générale NW -SE qui limite à l'est le plateau de Sra Ouertane de la zone effondrée de Xsour-nord Rohia est formé en réalité par une suite d'accidents d'échelle kilométrique. Près d'Ain es Semda, à environ sept kilomètres au sud ouest de la ville de Ksour, cet accident montre un changement abrupt de direction, passant de N160° à N130°. Lors des compressions de direction NW -SE du Miocène supérieur au Quaternaire, cet accident rejoue en décrochement dextre. Il met en contact des séries récentes d'âge pléistocène moyen à supérieur contre des séries crétacées. Son changement brutal de direction près d'Aïn es Semda est à l'origine des déformations locales en rapport avec la géométrie de l'accident Les séries quaternaires déformées sur la bordure du décrochement majeur montrent à plus petite échelle, sur les courbures en compression, des failles décrochantes à composantes inverses formant des structures en coin extrusif de type «pop up». Ces déformations compressives locales s'intègrent bien dans le cadre de la déformation régionale. Elles montrent l'étroite relation entre la déformation locale et le changement abrupt de la géométrie de l'accident décrochant dextre de Ksour.Zaier A., Chihi Lassaâd. Déformations compressives d'âge pléistocène moyen à supérieur liées à la géométrie de failles décrochantes près d'Aïn es Semda (Tunisie centrale). In: Géologie Méditerranéenne. Tome 24, numéro 3-4, 1997. pp. 153-159

Design of Biomechanical Legs with a Passive Toe Joint for Enhanced Human-like Walking

This paper presents the design procedure of a biomechanical leg, with a passive toe joint, which is capable of mimicking the human walking. This leg has to provide the major features of human gait in the motion trajectories of the hip, knee, ankle, and toe joints. Focus was given to the approach of designing the passive toe joint of the biomechanical leg in its role and effectiveness in performing human like motion. This study was inspired by experimental and theoretical studies in the fields of biomechanics and robotics. Very light materials were mainly used in the design process. Aluminum and carbon fiber parts were selected to design the proposed structure of this biomechanical leg, which is to be manufactured in the Mechanical Lab of the Sultan Qaboos University (SQU). The capabilities of the designed leg to perform the normal human walking are presented. This study provides a noteworthy and unique design for the passive toe joint, represented by a mass-spring damper system, using torsion springs in the foot segment. The working principle and characteristics of the passive toe joint are discussed.  Four-designed cases, with different design parameters, for the passives toe joint system are presented to address the significant role that the passive toe joint plays in human-like motion. The dynamic motion that is used to conduct this comparison was the first stage of the stance motion. The advantages of the presence of the passive toe joint in gait, and its effect on reducing the energy consumption by the other actuated joints are presented and a comparison between the four-designed cases is discussed

HOT AND COLD CYCLES FOR AFRICAN EMERGING SHARE IPO MARKET EVIDENCE FROM TUNISIA

ABSTRACT JEL Classification: C58, E37, G17. Contribution/ Originality This study has two contributions. First, it is one of few studies detecting IPO cycles and turning points of hot/cold periods for Tunisian share market. Second, with eight IPO activity measures, we use Markov switching models to detect IPOs cycles and test if these cycles are similar for different activity measures

Adaptive Compensator of Single State Elastoplastic Friction Model

A nonlinear friction is an unavoidable phenomenon frequently experienced in mechanical system between two contact surfaces. An adaptive compensator is designed to achieve tracking of a desired velocity trajectory in the presence of friction force described by a single state elastoplastic friction model. The adaptive compensator includes an adaptive observer and a computed force controller. The closed loop system is shown to be stable using Lyapunov second method. Simulation results show the effectiveness of the proposed compensator

Annealing effects on the structural, electrical and optical properties of ZnO thin films prepared by thermal evaporation technique

Zinc oxide (ZnO) thin films have been prepared on glass substrates at room temperature by thermal evaporation technique using ZnO powders and then are annealed at different temperatures ranging from 200 °C to 500 °C for 2 h in air. The effect of the annealing temperature (Tr) on the structural, optical and electrical properties of the ZnO thin films was studied. Experimental results show that annealing temperature has an important role in the changes observed in the structural, optical and electrical properties of the ZnO thin films. The XRD measurements confirm that the thin films grown by this technique have good crystalline hexagonal wurtzite structures. The optical transmittance spectra show transmittance higher about ∼90% within the visible wavelength region. Hence, the values of the gap are found to be between 3.13 and 3.25 eV. The resistivity values of the films have changed between 2.10−3 and 4.10−2 Ω cm with annealing temperature