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The Atlas cedar (Cedrus atlantica) is an emblematic species of Morocco, classified by the International Union for the Conservation of Nature (IUCN) in the red list of endangered species. Determining its potential area under current climatic conditions is an essential step in planning and ensuring its conservation. In this paper, we applied the maximum-entropy algorithm (MaxEnt) to predict the current and potential distribution of the Atlas cedar in order to provide a basis for its conservation. The adjusted model had an excellent predictive quality (AUC = 0.967). The most significant variables influencing the distribution of Atlas cedar, under current climatic conditions, are the precipitation in the driest quarter, precipitation in the driest month, average annual temperature and relative humidity. The model developed made it possible to establish the first map of the suitable potential area of the Atlas cedar in Morocco. The results obtained will guide managers to identify favorable sites for the rehabilitation of the Atlas cedar threatened with extinction. [ABSTRACT FROM AUTHOR]

Chronic constipation is a frequent intestinal functional dysfunction. Its symptoms are different in groups of people, characterized by a sensation of incomplete evacuation, infrequent defecations (less than 3 per week), or difficulty to defecate, for at least 6 months. New ROME IV criteria have been defined. They make a distinction between the Irritable Bowel Syndrome with constipation and functional constipation. The aims of this paper are to highlight the novelties about the pathophysiology and the treatment of the constipation. Concerning pathophysiological mechanisms, the role of the microbiota in constipation and the laxative action of biliary acids has been recently demonstrated. New treatments include secretagogues which increase the secretion of chlorine, Elobixat which reduces the reabsorption of biliary acids and probiotics which change the composition of microbiota. The neurostimulation of sacral nerves is in development. Some treatments have been proposed for constipation induced by opioids. They act on peripherical antagonists of opioid receptor. [ABSTRACT FROM AUTHOR]

Many machine learning algorithms use entropy measures as a criterion of construction that they seek to optimize. Among the most applied measures, Shannon's entropy is certainly the most known. However, in the real world applications, the use of the entropy measure turns out to be totally inadequate both in theory and in practice. Indeed, many hypothesis are in fact implicitly assumed whereas they are unfounded, therefore unjustified. In this paper, we will try to identify those hypothesis and we will demonstrate that they are unsuitable in machine learning with real data. Then, we will introduce, intuitively, a set of new prosperities that should be required for measures that are supposed to lead to efficients algorithms. [ABSTRACT FROM AUTHOR]

Objective: To present points of agreement and disagreement about antipsychotics. Since the appearance of 2nd generation long-acting antipsychotics (LAA), and given the high frequency of noncompliance with antipsychotics in psychotic disorders, LAAs have attracted more interest in psychiatriv literature. However, their use is suboptimal, globally, and is also subject to significant national disparities. ln this context, the Association des médecins psychiatres du Québec (AMPQ) has asked for a review of the evidence concerning LAA efficiency and tolerance, and has called for consensual clinical reflection on the benefits and obstacles of prescribing them, as weil as potential solutions, including administrative and judiciary dimensions. Methods: The AMPQ established an expert committee, from 4 Quebec universities, which was responsible for preparing the review paper. The committee intended to appropriately provide c1inicians with the different aspects of LAA use. The committee produced a qualitative and selective review. Results: Mean LAA prescription rates observed in Canada are around 6% and data to confirm this are scarce. A 15% to 25% rate could be suggested. Conclusion: The committee has submitted the Quebec long-acting antipsychotic algorithm (QAAPAPLE, derived from the French acronym) as a result of the consensus reached by the 4 university psychiatry departments. [ABSTRACT FROM AUTHOR]

Abstract: A granular structure is an aggregation of grains whose sizes are characterized by a given distribution. A sample of this kind of structure is often modeled by a rectangle filled with disks in two dimensions or a parallelepiped containing spherical balls in three dimensions. Therefore, the geometrical modeling of such a structure consists in determining a “dense” repartition of disjoint disks (or spherical balls) with respect to the specified size distribution. In this paper, a new sphere packing algorithm based on an advancing-front approach, commonly used in meshing methods, is proposed. Significant improvements in computing time and density have been obtained comparing to existing methods. In addition, we show that the generated circular grains can be transformed into polygonal (polyhedral) cells generally observed in reality. An example of a metallic nanostructure model is presented. To cite this article: P. Laug et al., C. R. Mecanique 336 (2008). [Copyright &y& Elsevier]

Pocket milling is an essential issue in rough milling. Although machining capacities have been strongly modified, no significant evolution was observed about pocket milling trajectories. Trochoïds and plunge milling are new types of strategies which have found practical applications in hard materials rough milling. This paper aims at evaluating their potential in rough pocket milling of aluminium alloys. Algorithms were developed to generate trochoïdal and plunge cutting trajectories for pocket milling, with cycle time optimisation regarding to milled surfaces quality. An experimental campaign has also been done and focused both on productivity and quality issues. Two different high speed milling machine tools were tested: a serial three-axis machine tool and a parallel kinematics five-axis machine tool. The results of this work leads to a better definition of the strengths and weaknesses of trochoïdal milling and plunge cutting strategies in aluminium alloys rough machining with the focus to optimize the choice of strategies. [ABSTRACT FROM AUTHOR]

This paper presents a study of the tool path adaptation to the HSM machining process. The definition of an efficient process imposes the common selection of the milling method and of the cutting conditions. Concerning the tool path programming, the user must choose a milling method and an algorithm dedicated to the part to be machined. The computed tool path does not introduce a reduction of the productivity by appearance of perturbations on the kinematical behaviour of the machine tool and on the mechanical behaviour of the tool. To reduce the influence of the perturbations, CAM software proposes many solutions and options. It is then difficult to choose and to define a machining operation. After an analysis of difficulties due to such part, we present a problem classification. According to the requirement, such classification simplifies the choice of the machining method. [ABSTRACT FROM AUTHOR]

While improving the dynamical performance of a flexible motion control system, additional stresses are generated which induce undesirable vibrations. The design of adequate control algorithms makes it possible to enhance the overall behaviour of the machine while limiting its deformation modes vibrations. This paper presents a comparative study of the influence of different control algorithms on the trade-off between the cycle time and the amplitude of the residual vibrations, which have been applied to a Cartesian robot. While this selection of control algorithms is not exhaustive, these can all easily be implemented in current industrial systems. Each selected control algorithm is analysed along with experimental validations. [ABSTRACT FROM AUTHOR]

Functional tolerancing requires calculating the influence of all the deviations admitted on the parts by their definition drawings according to ISO standards' to check the respect of the functional requirements. The method CLIC (Tolerancing in Localization with Influence of the Contacts) includes algorithms of choice of the specifications, an original and complete 3D method of calculation of the result based on the "analysis lines", at worse cases and in statistic, and a method of synthesis of the tolerances. This paper presents the influence of the deviations of a junction on the requirement and the decomposition of a complex requirement in sub-requirements. A three-dimensional statistical application is proposed with a presentation of the worksheet Microsoft EXCEL. [ABSTRACT FROM AUTHOR]

Abstract: In this paper a new algorithm for detection of suspicious mass area from mammographic images is presented. It uses histogram modification enhancement technique and a segmentation method based on minimization of inertia sum. The histogram modification filter is designed so as to be able to enhance disease patterns of suspected masses by cleaning up unrelated background clutters. Segmentation is then performed on the enhanced-image to localize the suspected mass areas using minimisation of inertia sum of images intensity classes. The proposed algorithm was tested on a database of 32 mammogramms provided by Gynaeco-obstetric and pediatric hospital of Yaoundé on which masses had previously been localised by experienced radiologists. Results show that the algorithm is able to identify masses in all cases presented with a sensibility of 94% approximately. In addition, we found out that sizes and edges of masses detected are similar to those marked by radiologists. Furthermore in some cases, we could detect some hidden masses that the radiologists were not able to mark out. [Copyright &y& Elsevier]

Abstract: The bi-potential method has been successfully applied for the modeling of frictional contact problems in static cases. This paper presents the application of this method for dynamic analysis of impact problems with multiple deformable bodies. A first order algorithm is applied for numerical integration of the time-discretized equation of motion. The numerical results show clearly the physical energy dissipation introduced by frictional effects between the solids in contact. To cite this article: B. Magnain et al., C. R. Mecanique 333 (2005). [Copyright &y& Elsevier]

Three-dimensional reconstruction techniques are widely used to provide a spatial description of scoliotic spines. One example is the 3-D reconstruction method developed and routinely used at Sainte-Justine Hospital. It concerns the reconstruction of six anatomical landmarks per vertebra from the frontal and lateral radiographs: endplate centers; inferior and superior tips of both pedicles. Although this “standard” method is accurate, it requires 2 h for an expert technician to identify all anatomical landmarks on radiographs.Objective. – Therefore, this paper presents a novel and fast computed acquisition method providing a reconstruction of the spine better suited to the needs of the orthopedists during scoliosis clinics.Materials and Methods. – In this approach, five to eight points are identified on the frontal and lateral radiographs to obtain the overall shape of the spine. 2-D average predictive models, are built from a database of 791 radiographs, allowing to estimate the 2-D coordinates of the six vertebral landmarks and to obtain their 3-D coordinates from the DLT algorithm.Results and conclusions. – The evaluation of this “fast method” shows that the minimum number of points to be identified on the frontal radiograph is six for right thoracic or left lumbar curves and eight for right thoracic–left lumbar curves. Seven points need to be identified on the lateral radiograph. Furthermore, average models corresponding to a specific type and severity of scoliosis allow the 2-D mean differences between “standard” and “fast” methods to be less than 3.7 mm for endplate landmarks and 5.0 mm for pedicles. No significant difference was found between clinical indices obtained from both methods, confirming that the “fast” method is well adapted for direct clinical use. [Copyright &y& Elsevier]

This paper presents a study devoted to the composite fabric shaping simulation in finite strain analysis. We introduce a new geometrical approach based on the fishnet method for which the deformation of a fabric mesh element consists in a pure trellis effect. Such a fabric mesh element is then defined by a curved quadrilateral whose edges are geodesic lines with the same length plotted onto the surface to drape. Given three vertices of the fabric mesh element on the surface, we propose an optimization algorithm to define the fourth vertex of the fabric mesh element. This algorithm allows us to drape the surface using an advancing front approach from the data of an initial impact point between the fabric and the surface and the initial fibre directions at this point. A numerical draping simulation example using this approach is given. To cite this article: H. Borouchaki, A. Cherouat, C. R. Mecanique 331 (2003). [Copyright &y& Elsevier]

Abstract: Constant progress in medical imaging and particularly magnetic resonance imaging has profound impact in planning for stereotactic radiosurgery and radiotherapy. The purpose of this paper is to discuss the integration of medical imaging modalities in the planning process. Principles of generic algorithms to calculate stereotactic coordinates are treated for tomographic imaging and digital substraction angiography, and their accuracies are analyzed in a review of the literature. The algorithmic foundations and performance of automatic intermodality co-registration methods are developed. Finally, the MRI sequences useful in planning and follow-up are discussed and the role of MR angiographic sequences compared to conventional X-ray angiography in the particular case of the arteriovenous malformation planning. [Copyright &y& Elsevier]