512 research outputs found

    Analyzing supply response of fruit tree products in Tunisia: The case of peaches

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    In Tunisia, peaches have a significant place in the fruit tree sector. Planted areas have been expanding ever since the eighties as a result of irrigation water extension and the use of better yielding varieties. These factors resulted in high production levels and fruit exports thereof. However, important seasonal and annual variation of fruit supplies continues to characterize prices at both wholesale and consumption levels. To study the response of peach production an econometric model was developed. Modelling was carried out in two stages. First area variation was explained through new plantings and removals and second yield variation was analyzed. The methodological approach followed takes into account the characteristics and specificities related to perennial crops. Weak response of supply to variations in expected prices was obtained. Supply price elasticity was estimated about 0.13 suggesting a high degree of inelasticity.Supply response, modeling, price expectations, peaches, Demand and Price Analysis,

    Renewable Energy in Eastern North Africa in Terms of Patterns of Coupling to Czisch European HVDC Super Grid

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    In this study, wind energy potential and perspectives in the eastern North Africa region (Tunisia) have been investigated in terms of connectivity to the projected Czisch European HVDC super grid. A simplified extracted scheme of this grid has been used as a guide to optimize transportation efficiency through the whole net. Wind, as an available and easily exploitable renewable energy was showing to have a promising future for 2025 horizon in the context of a connected net with the European Union, despite local sub-grids disparities. This is also to emphasis HVDC technology adequacy for economical power transmission over very long distances andconnection between differently established grids

    A Numerical Approach for Solving Optimal Control Problems Using the Boubaker Polynomials Expansion Scheme

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    In this paper, we present a computational method for solving optimal control problems and the controlled Duffing oscillator. This method is based on state parametrization. In fact, the state variable is approximated by Boubaker polynomials with unknown coefficients. The equation of motion, performance index and boundary conditions are converted into some algebraic equations. Thus, an optimal control problem converts to a optimization problem, which can then be solved easily. By this method, the numerical value of the performance index is obtained. Also, the control and state variables can be approximated as functions of time. Convergence of the algorithms is proved. Numerical results are given for several test examples to demonstrate the applicability and efficiency of the method

    An ethnobotanical study of medicinal plants of the Agadir Ida Ou Tanane province (southwest Morocco)

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    Objective: As part of the development of natural heritage of Morocco, an ethnobotanical study was conducted in the region of Agadir Ida Ou Tanane (Southwest Morocco) with the aim to collect detailed information about the usage of plants in human therapy.Methodology and results: The survey was carried out over a period of 24 months, by means of semi-structured and structured interviews. A total of 400 interviews were done with traditional health practitioners and knowledgeable villagers. Data collected was on, vernacular names of plants, their uses, parts used and mode of preparation. Other information about users was also collected such as age, sex, level of education. A total of 110 plants species belonging to 53 families and 95 genera were inventoried with 7.27 % of the species endemic to Morocco. Plants frequently used were: Thymus satureioides (Tazouknnit, Zaitra), Thymus broussonnetii (Azoukni, Zaater), Argania spinosa (Argan), Tetraclinis articulata (Azouka, Aùrar) and Lavandula dentate (Igerch, Halhal). The elderly (more than 50 years) have more knowledge in medicinal plants with regard to the other age groups, this indicates that knowledge was acquired by long experience accumulated.Conclusion and application of results: This survey shows that traditional medicine is still used and constituted a very rich heritage in Agadir Ida Ou Tanane Region. The collected data may help to avoid the loss of traditional knowledge on the use of medicinal plants detained in the study area, and represent the preliminary information required in view of a future phytochemical investigation on the most used plants.Key words: Ethnobotanical survey, medicinal plants, phytotherapy, Agadir Ida Ou Tanane province, southwest of Morocco

    Subependymome du ventricule lateral: presentation d’une serie de 5 cas et revue de la litterature.

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    Description Les subĂ©pendymomes sont des tumeurs bĂ©nignes rares, de dĂ©couverte souvent fortuite et siĂ©geant prĂ©fĂ©rentiellement au niveau du quatriĂšme ventricule, plus rarement au niveau du ventricule latĂ©ral.Objectif Le but de notre Ă©tude est de prĂ©senter notre expĂ©rience en matiĂšre de subĂ©pendymomes du ventricule latĂ©ral et de discuter leurs caractĂ©ristiques cliniques, radiologiques, de prise en charge et pronostiques au vu des donnĂ©es actuelles de la littĂ©rature.MĂ©thode Etude rĂ©trospective de cinq cas de subĂ©pendymomes symptomatiques du ventricule latĂ©ral pris en charge au sein de notre institution au cours des dix derniĂšres annĂ©es.RĂ©sultats Cinq sujets de sexe masculin avec des subĂ©pendymomes histologiquement prouvĂ©s ont Ă©tĂ© recensĂ©s. L’ñge moyen Ă©tait de 35.2 ans. La prĂ©sentation clinique allait du dĂ©but brutal avec aggravation rapide de l’état neurologique aux formes insidieuses avec syndrome d’hypertension intracrĂąnienne Ă©voluant depuis un an. La tumeur Ă©tait confinĂ©e au ventricule latĂ©ral dans trois cas et Ă©tendue au troisiĂšme ventricule dans les deux autres cas avec une taille allant de 12 Ă  42 mm. L’exĂ©rĂšse complĂšte par un abord trans calleux Ă©tait rĂ©alisĂ©e dans tous les cas. L’évolution Ă©tait favorable avec absence de rĂ©cidive aprĂšs un suivi moyen de 6 ans 2 mois.Conclusion Les subĂ©pendymomes du ventricule latĂ©ral sont rares, avec une symptomatologie variable et une Ă©volution imprĂ©visible. La chirurgie est la modalitĂ© thĂ©rapeutique de choix et l’exĂ©rĂšse totale doit ĂȘtre envisagĂ©e dans tous les cas.Mots clĂ©s : Chirurgie, Imagerie par rĂ©sonance magnĂ©tique, SubĂ©pendymome, Ventricule latĂ©ral, SubĂ©pendymome, Ventricule latĂ©ra

    Axillary Sentinel Lymph Node Biopsy for Breast Cancer and Melanoma Patients after Previous Axillary Surgery: A Systematic Review

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    Objective: Sentinel lymph node biopsy (SLNB) is a validated staging technique for breast carcinoma. Some women are exposed to have a second SLNB due to breast cancer recurrence or a second neoplasia (breast or other). Due to modi- fied anatomy, it has been claimed that previous axillary surgery represents a contra-indication to SLNB. Our objective was to analyse the literature to assess if a second SLNB is to be recommended or not. Methods: For the present study, we performed a review of all published data during the last 10 years on patients with previous axilla surgery and second SLNB. Results: Our analysis shows that second SLNB is feasible in 70%. Extra-axillary SNs rate (31%) was higher after radical lymph node dissection (ALND) (60% - 84%) than after SLNB alone (14% - 65%). Follow-up and com- plementary ALND following negative and positive second SLNB shows that it is a reliable procedure. Conclusion: The review of literature confirms that SLNB is feasible after previous axillary dissection. Triple technique for SN mapping is the best examination to highlight modified lymphatic anatomy and shows definitively where SLNB must be per- formed. Surgery may be more demanding as patients may have more frequently extra-axillary SN only, like internal mammary nodes. ALND can be avoided when second SLNB harvests negative SNs. These conclusions should however be taken with caution because of the heterogeneity of publications regarding SLNB and surgical technique

    Influence of annealing and processing conditions on nano-structured thin films of tungsten trioxide

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    Transition metal oxides represent a novel class of compounds which have attracted a considerable interest in the recent literature. Among these materials, tungsten trioxide has shown great potential due to photo-oxidation of water with visible light, high photocurrent with nano-crystals and good sensing properties towards several gases. The purpose of this study is to investigate the influence of conditions of heat treatment on properties of WO3 thin films prepared by hermal evaporation under vacuum. Physico-chemical properties of WO3 thin layers for different heat processing conditions were determined by X-ray diffraction XRD, microprobe electronics and scanning electron microscopy (SEM).Optical measurement yieldedt ransmission and reflection measurements. The study of the physicochemical properties of thin layers of thermally post-treated tungsten trioxide showed that layers processed under vacuum have an unidentifiable structure than those annealed in air and crystallized under different crystallographic structures depending on processing temperature. Layers annealed in oxygen hadmonoclinic crystalline structures.It has been recorded that crystallinity and transmission of these films were drastically improved

    ‘Chemlali Mhassen’: New olive cultivar derived from crossbreeding program in Tunisia with high oil quality and productivity

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    The new olive cultivar ‘Chemlali Mhassen’ was derived from the autopollination of the Tunisian oil cultivar ‘Chemlali Sfax’. The main morphological differences between the two cultivars were observed on the endocarp (symmetry, position of maximum diameter, apex, base and surface). On the agronomic plan, this cultivar is distinguishable from the original cultivar due to its medium earliness of bearing (4 years), medium alternate bearing (0.44), early ripening, moderate sensitivity to verticillium and its high olive production per tree (7.7 kg). Concerning oil quality, ‘Chemlali Mhassen’ had higher performances than the original cultivar for oleic acid content (70 to 77 %) and lower contents for palmitic acid (9.2 to 11.5 %) and linoleic acid (9.3 to 14.7 %). Similar performances were recorded between the new and the original cultivars for rhizogenesis behavior and pollen compatibility

    Physical investigations on (In2S3)x(In2O3)y and In2S3-xSex thin films processed through In2S3 annealing in air and selenide atmosphere

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    In2S3-xSex and (In2S3)x(In2O3)y thin films have been prepared on glass substrates using appropriate heat treatments of In evaporatedt hin films. X-ray analysis shows that In thin films which were annealed under sulfur atmosphere at 350°C were mainly formed by In2S3. A heat treatment o fthis binary in air at 400°C during one hour leads to (In2S3)x(In2O3)y ternary material which has a tetragonal structure with a preferred orientation of the crystallites along the (109) direction. Similarly, a heat treatment of In2S3 in selenium atmosphere at 350°C during six hours leads to a new In2S3-xSex ternary material having tetragonal body centered structure with a preferred orientation of the crystallites along the (109) direction.Optical band gap,refractive index and extinction coefficient values of In2S3-xSex and (In2S3)x(In2O3)y thin films have been reached. Moreover, correlations between optical conductivity, XRD, AFM and Urbach energy of such ternary thin films have been discussed. Finally, the recorded formation disparity between the quaternary (In2S3)x(In2O3)y and ternary In2S3-xSex compounds has been discussed in terms of the Simha–Somcynsky and Lattice Compatibility theories
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